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DOE OSTI2020

Materials Data on Hf2N2O by Materials Project

Hf2ON2 is Ilmenite-like structured and crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are sixteen inequivalent Hf4+ sites. In the first Hf4+ site, Hf4+ is bonded to four N3- and two O2- atoms to form distorted HfN4O2 octahedra that share corners with six HfN3O3 octahedra and edges with six HfN4O2 octahedra. The corner-sharing octahedra tilt angles range from 50–57°. There are a spread of Hf–N bond distances ranging from 2.08–2.19 Å. There are one shorter (2.23 Å) and one longer (2.29 Å) Hf–O bond lengths. In the second Hf4+ site, Hf4+ is bonded to four N3- and two O2- atoms to form a mixture of edge and corner-sharing HfN4O2 octahedra. The corner-sharing octahedra tilt angles range from 52–58°. There are a spread of Hf–N bond distances ranging from 2.10–2.19 Å. There are one shorter (2.21 Å) and one longer (2.25 Å) Hf–O bond lengths. In the third Hf4+ site, Hf4+ is bonded to four N3- and two O2- atoms to form a mixture of distorted edge and corner-sharing HfN4O2 octahedra. The corner-sharing octahedra tilt angles range from 53–56°. There are a spread of Hf–N bond distances ranging from 2.08–2.17 Å. There are one shorter (2.29 Å) and one longer (2.31 Å) Hf–O bond lengths. In the fourth Hf4+ site, Hf4+ is bonded to three N3- and three O2- atoms to form distorted HfN3O3 octahedra that share corners with six HfN5O octahedra and edges with six HfN4O2 octahedra. The corner-sharing octahedra tilt angles range from 52–56°. There are a spread of Hf–N bond distances ranging from 2.10–2.23 Å. There are a spread of Hf–O bond distances ranging from 2.11–2.23 Å. In the fifth Hf4+ site, Hf4+ is bonded to three N3- and three O2- atoms to form a mixture of distorted edge and corner-sharing HfN3O3 octahedra. The corner-sharing octahedra tilt angles range from 49–57°. There are a spread of Hf–N bond distances ranging from 2.08–2.21 Å. There are a spread of Hf–O bond distances ranging from 2.11–2.23 Å. In the sixth Hf4+ site, Hf4+ is bonded to five N3- and one O2- atom to form a mixture of distorted edge and corner-sharing HfN5O octahedra. The corner-sharing octahedra tilt angles range from 53–56°. There are a spread of Hf–N bond distances ranging from 2.11–2.20 Å. The Hf–O bond length is 2.27 Å. In the seventh Hf4+ site, Hf4+ is bonded to three N3- and three O2- atoms to form HfN3O3 octahedra that share corners with six HfN4O2 octahedra and edges with six HfN3O3 octahedra. The corner-sharing octahedra tilt angles range from 51–58°. There are two shorter (2.07 Å) and one longer (2.12 Å) Hf–N bond lengths. There are one shorter (2.21 Å) and two longer (2.26 Å) Hf–O bond lengths. In the eighth Hf4+ site, Hf4+ is bonded to five N3- and one O2- atom to form distorted HfN5O octahedra that share corners with six HfN4O2 octahedra and edges with six HfN3O3 octahedra. The corner-sharing octahedra tilt angles range from 53–58°. There are a spread of Hf–N bond distances ranging from 2.12–2.25 Å. The Hf–O bond length is 2.34 Å. In the ninth Hf4+ site, Hf4+ is bonded to five N3- and one O2- atom to form a mixture of edge and corner-sharing HfN5O octahedra. The corner-sharing octahedra tilt angles range from 54–58°. There are a spread of Hf–N bond distances ranging from 2.10–2.23 Å. The Hf–O bond length is 2.30 Å. In the tenth Hf4+ site, Hf4+ is bonded to three N3- and three O2- atoms to form a mixture of distorted edge and corner-sharing HfN3O3 octahedra. The corner-sharing octahedra tilt angles range from 49–56°. There are a spread of Hf–N bond distances ranging from 2.12–2.20 Å. There are a spread of Hf–O bond distances ranging from 2.13–2.17 Å. In the eleventh Hf4+ site, Hf4+ is bonded to four N3- and two O2- atoms to form HfN4O2 octahedra that share corners with six HfN3O3 octahedra and edges with six HfN4O2 octahedra. The corner-sharing octahedra tilt angles range from 53–58°. There are a spread of Hf–N bond distances ranging from 2.10–2.18 Å. There are one shorter (2.26 Å) and one longer (2.27 Å) Hf–O bond lengths. In the twelfth Hf4+ site, Hf4+ is bonded to five N3- and one O2- atom to form a mixture of distorted edge and corner-sharing HfN5O octahedra. The corner-sharing octahedra tilt angles range from 52–58°. There are a spread of Hf–N bond distances ranging from 2.15–2.23 Å. The Hf–O bond length is 2.22 Å. In the thirteenth Hf4+ site, Hf4+ is bonded to three N3- and three O2- atoms to form a mixture of distorted edge and corner-sharing HfN3O3 octahedra. The corner-sharing octahedra tilt angles range from 49–57°. There are a spread of Hf–N bond distances ranging from 2.06–2.20 Å. There are a spread of Hf–O bond distances ranging from 2.13–2.24 Å. In the fourteenth Hf4+ site, Hf4+ is bonded to four N3- and two O2- atoms to form distorted HfN4O2 octahedra that share corners with six HfN4O2 octahedra and edges with six HfN5O octahedra. The corner-sharing octahedra tilt angles range from 50–54°. There are a spread of Hf–N bond distances ranging from 2.16–2.18 Å. There are one shorter (2.16 Å) and one longer (2.17 Å) Hf–O bond lengths. In the fifteenth Hf4+ site, Hf4+ is bonded to five N3- and one O2- atom to form a mixture of distorted edge and corner-sharing HfN5O octahedra. The corner-sharing octahedra tilt angles range from 49–57°. There are a spread of Hf–N bond distances ranging from 2.13–2.23 Å. The Hf–O bond length is 2.22 Å. In the sixteenth Hf4+ site, Hf4+ is bonded to four N3- and two O2- atoms to form a mixture of distorted edge and corner-sharing HfN4O2 octahedra. The corner-sharing octahedra tilt angles range from 53–58°. There are a spread of Hf–N bond distances ranging from 2.12–2.24 Å. There are one shorter (2.18 Å) and one longer (2.21 Å) Hf–O bond lengths. There are sixteen inequivalent N3- sites. In the first N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share a cornercorner with one NHf4 tetrahedra, corners with five NHf4 trigonal pyramids, corners with six OHf4 trigonal pyramids, an edgeedge with one NHf4 tetrahedra, an edgeedge with one NHf4 trigonal pyramid, and edges with two OHf4 trigonal pyramids. In the second N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 tetrahedra that share corners with two NHf4 tetrahedra, corners with two OHf4 trigonal pyramids, corners with eight NHf4 trigonal pyramids, an edgeedge with one NHf4 trigonal pyramid, and edges with three OHf4 trigonal pyramids. In the third N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share corners with two NHf4 tetrahedra, corners with two OHf4 trigonal pyramids, corners with eight NHf4 trigonal pyramids, an edgeedge with one NHf4 trigonal pyramid, and edges with three OHf4 trigonal pyramids. In the fourth N3- site, N3- is bonded to four Hf4+ atoms to form NHf4 trigonal pyramids that share corners with six NHf4 trigonal pyramids, corners with six OHf4 trigonal pyramids, an edgeedge with one NHf4 tetrahedra, and edges with three NHf4 trigonal pyramids. In the fifth N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share corners with five OHf4 trigonal pyramids, corners with seven NHf4 trigonal pyramids, an edgeedge with one NHf4 tetrahedra, an edgeedge with one OHf4 trigonal pyramid, and edges with two NHf4 trigonal pyramids. In the sixth N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 tetrahedra that share a cornercorner with one NHf4 tetrahedra, corners with five OHf4 trigonal pyramids, corners with six NHf4 trigonal pyramids, edges with two NHf4 trigonal pyramids, and edges with two OHf4 trigonal pyramids. In the seventh N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share a cornercorner with one NHf4 tetrahedra, corners with five NHf4 trigonal pyramids, corners with six OHf4 trigonal pyramids, an edgeedge with one NHf4 tetrahedra, an edgeedge with one OHf4 trigonal pyramid, and edges with two NHf4 trigonal pyramids. In the eighth N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share corners with three NHf4 tetrahedra, corners with two OHf4 trigonal pyramids, corners with seven NHf4 trigonal pyramids, an edgeedge with one NHf4 trigonal pyramid, and edges with three OHf4 trigonal pyramids. In the ninth N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share corners with three NHf4 tetrahedra, corners with two OHf4 trigonal pyramids, corners with seven NHf4 trigonal pyramids, edges with two NHf4 trigonal pyramids, and edges with two OHf4 trigonal pyramids. In the tenth N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share a cornercorner with one NHf4 tetrahedra, corners with five OHf4 trigonal pyramids, corners with six NHf4 trigonal pyramids, an edgeedge with one OHf4 trigonal pyramid, and edges with three NHf4 trigonal pyramids. In the eleventh N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 tetrahedra that share a cornercorner with one NHf4 tetrahedra, corners with five OHf4 trigonal pyramids, corners with six NHf4 trigonal pyramids, edges with two NHf4 trigonal pyramids, and edges with two OHf4 trigonal pyramids. In the twelfth N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share a cornercorner with one NHf4 tetrahedra, corners with five NHf4 trigonal pyramids, corners with six OHf4 trigonal pyramids, an edgeedge with one NHf4 tetrahedra, and edges with three NHf4 trigonal pyramids. In the thirteenth N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share corners with six NHf4 trigonal pyramids, corners with six OHf4 trigonal pyramids, an edgeedge with one OHf4 trigonal pyramid, and edges with three NHf4 trigonal pyramids. In the fourteenth N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share corners with three NHf4 tetrahedra, corners with three OHf4 trigonal pyramids, corners with six NHf4 trigonal pyramids, edges with two NHf4 trigonal pyramids, and edges with two OHf4 trigonal pyramids. In the fifteenth N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share corners with three NHf4 tetrahedra, corners with three OHf4 trigonal pyramids, corners with six NHf4 trigonal pyramids, an edgeedge with one OHf4 trigonal pyramid, and edges with three NHf4 trigonal pyramids. In the sixteenth N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share corners with two NHf4 tetrahedra, corners with two OHf4 trigonal pyramids, corners with eight NHf4 trigonal pyramids, edges with two NHf4 trigonal pyramids, and edges with two OHf4 trigonal pyramids. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded to four Hf4+ atoms to form distorted OHf4 trigonal pyramids that share corners with five OHf4 trigonal pyramids, corners with seven NHf4 trigonal pyramids, edges with two NHf4 tetrahedra, and edges with two NHf4 trigonal pyramids. In the second O2- site, O2- is bonded to four Hf4+ atoms to form OHf4 trigonal pyramids that share corners with five OHf4 trigonal pyramids, corners with seven NHf4 trigonal pyramids, an edgeedge with one NHf4 tetrahedra, and edges with three NHf4 trigonal pyramids. In the third O2- site, O2- is bonded to four Hf4+ atoms to form distorted OHf4 trigonal pyramids that share corners with three NHf4 tetrahedra, corners with two OHf4 trigonal pyramids, corners with seven NHf4 trigonal pyramids, an edgeedge with one OHf4 trigonal pyramid, and edges with three NHf4 trigonal pyramids. In the fourth O2- site, O2- is bonded to four Hf4+ atoms to form OHf4 trigonal pyramids that share corners with two NHf4 tetrahedra, corners with three OHf4 trigonal pyramids, corners with seven NHf4 trigonal pyramids, an edgeedge with one OHf4 trigonal pyramid, and edges with three NHf4 trigonal pyramids. In

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Hf2N2O by Materials Project

Hf2ON2 is Ilmenite-like structured and crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are sixteen inequivalent Hf4+ sites. In the first Hf4+ site, Hf4+ is bonded to two N3- and four O2- atoms to form a mixture of edge and corner-sharing HfN2O4 octahedra. The corner-sharing octahedra tilt angles range from 51–55°. There are one shorter (2.12 Å) and one longer (2.15 Å) Hf–N bond lengths. There are a spread of Hf–O bond distances ranging from 2.10–2.15 Å. In the second Hf4+ site, Hf4+ is bonded to four N3- and two O2- atoms to form distorted HfN4O2 octahedra that share corners with six HfN2O4 octahedra and edges with six HfN4O2 octahedra. The corner-sharing octahedra tilt angles range from 52–57°. There are a spread of Hf–N bond distances ranging from 2.12–2.24 Å. There are one shorter (2.13 Å) and one longer (2.23 Å) Hf–O bond lengths. In the third Hf4+ site, Hf4+ is bonded to four N3- and two O2- atoms to form distorted HfN4O2 octahedra that share corners with six HfN4O2 octahedra and edges with six HfN2O4 octahedra. The corner-sharing octahedra tilt angles range from 52–58°. There are a spread of Hf–N bond distances ranging from 2.13–2.24 Å. There are one shorter (2.14 Å) and one longer (2.18 Å) Hf–O bond lengths. In the fourth Hf4+ site, Hf4+ is bonded to four N3- and two O2- atoms to form distorted HfN4O2 octahedra that share corners with six HfN2O4 octahedra and edges with six HfN4O2 octahedra. The corner-sharing octahedra tilt angles range from 49–56°. There are a spread of Hf–N bond distances ranging from 2.13–2.22 Å. There are one shorter (2.15 Å) and one longer (2.18 Å) Hf–O bond lengths. In the fifth Hf4+ site, Hf4+ is bonded to three N3- and three O2- atoms to form distorted HfN3O3 octahedra that share corners with six HfN4O2 octahedra and edges with six HfN2O4 octahedra. The corner-sharing octahedra tilt angles range from 49–59°. There are a spread of Hf–N bond distances ranging from 2.07–2.20 Å. There are a spread of Hf–O bond distances ranging from 2.11–2.24 Å. In the sixth Hf4+ site, Hf4+ is bonded to four N3- and two O2- atoms to form distorted HfN4O2 octahedra that share corners with six HfN4O2 octahedra and edges with six HfN2O4 octahedra. The corner-sharing octahedra tilt angles range from 49–57°. There are a spread of Hf–N bond distances ranging from 2.10–2.19 Å. There are one shorter (2.19 Å) and one longer (2.28 Å) Hf–O bond lengths. In the seventh Hf4+ site, Hf4+ is bonded to four N3- and two O2- atoms to form a mixture of edge and corner-sharing HfN4O2 octahedra. The corner-sharing octahedra tilt angles range from 54–57°. There are a spread of Hf–N bond distances ranging from 2.16–2.20 Å. There are one shorter (2.15 Å) and one longer (2.17 Å) Hf–O bond lengths. In the eighth Hf4+ site, Hf4+ is bonded to five N3- and one O2- atom to form a mixture of edge and corner-sharing HfN5O octahedra. The corner-sharing octahedra tilt angles range from 52–56°. There are a spread of Hf–N bond distances ranging from 2.11–2.21 Å. The Hf–O bond length is 2.29 Å. In the ninth Hf4+ site, Hf4+ is bonded to four N3- and two O2- atoms to form distorted HfN4O2 octahedra that share corners with six HfN4O2 octahedra and edges with six HfN2O4 octahedra. The corner-sharing octahedra tilt angles range from 50–57°. There are a spread of Hf–N bond distances ranging from 2.13–2.22 Å. There are one shorter (2.13 Å) and one longer (2.25 Å) Hf–O bond lengths. In the tenth Hf4+ site, Hf4+ is bonded to four N3- and two O2- atoms to form distorted HfN4O2 octahedra that share corners with six HfN2O4 octahedra and edges with six HfN4O2 octahedra. The corner-sharing octahedra tilt angles range from 50–59°. There are a spread of Hf–N bond distances ranging from 2.09–2.25 Å. There are one shorter (2.24 Å) and one longer (2.27 Å) Hf–O bond lengths. In the eleventh Hf4+ site, Hf4+ is bonded to five N3- and one O2- atom to form a mixture of edge and corner-sharing HfN5O octahedra. The corner-sharing octahedra tilt angles range from 55–59°. There are a spread of Hf–N bond distances ranging from 2.11–2.22 Å. The Hf–O bond length is 2.33 Å. In the twelfth Hf4+ site, Hf4+ is bonded to four N3- and two O2- atoms to form distorted HfN4O2 octahedra that share corners with six HfN2O4 octahedra and edges with six HfN4O2 octahedra. The corner-sharing octahedra tilt angles range from 49–59°. There are a spread of Hf–N bond distances ranging from 2.09–2.23 Å. There are one shorter (2.22 Å) and one longer (2.28 Å) Hf–O bond lengths. In the thirteenth Hf4+ site, Hf4+ is bonded to four N3- and two O2- atoms to form distorted HfN4O2 octahedra that share corners with six HfN4O2 octahedra and edges with six HfN2O4 octahedra. The corner-sharing octahedra tilt angles range from 50–58°. There are a spread of Hf–N bond distances ranging from 2.08–2.18 Å. There are one shorter (2.26 Å) and one longer (2.29 Å) Hf–O bond lengths. In the fourteenth Hf4+ site, Hf4+ is bonded to five N3- and one O2- atom to form distorted HfN5O octahedra that share corners with six HfN4O2 octahedra and edges with six HfN2O4 octahedra. The corner-sharing octahedra tilt angles range from 52–59°. There are a spread of Hf–N bond distances ranging from 2.12–2.27 Å. The Hf–O bond length is 2.23 Å. In the fifteenth Hf4+ site, Hf4+ is bonded to three N3- and three O2- atoms to form distorted HfN3O3 octahedra that share corners with six HfN2O4 octahedra and edges with six HfN4O2 octahedra. The corner-sharing octahedra tilt angles range from 50–56°. There are a spread of Hf–N bond distances ranging from 2.07–2.15 Å. There are a spread of Hf–O bond distances ranging from 2.13–2.25 Å. In the sixteenth Hf4+ site, Hf4+ is bonded to five N3- and one O2- atom to form distorted HfN5O octahedra that share corners with six HfN2O4 octahedra and edges with six HfN4O2 octahedra. The corner-sharing octahedra tilt angles range from 51–56°. There are a spread of Hf–N bond distances ranging from 2.15–2.24 Å. The Hf–O bond length is 2.18 Å. There are sixteen inequivalent N3- sites. In the first N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share a cornercorner with one NHf4 tetrahedra, corners with four OHf4 trigonal pyramids, corners with seven NHf4 trigonal pyramids, an edgeedge with one NHf4 trigonal pyramid, and edges with three OHf4 trigonal pyramids. In the second N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share corners with four OHf4 trigonal pyramids, corners with eight NHf4 trigonal pyramids, an edgeedge with one NHf4 tetrahedra, an edgeedge with one NHf4 trigonal pyramid, and edges with two OHf4 trigonal pyramids. In the third N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 tetrahedra that share corners with four OHf4 trigonal pyramids, corners with eight NHf4 trigonal pyramids, edges with two NHf4 trigonal pyramids, and edges with two OHf4 trigonal pyramids. In the fourth N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share corners with four OHf4 trigonal pyramids, corners with eight NHf4 trigonal pyramids, edges with two NHf4 trigonal pyramids, and edges with two OHf4 trigonal pyramids. In the fifth N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share corners with four OHf4 trigonal pyramids, corners with eight NHf4 trigonal pyramids, an edgeedge with one NHf4 tetrahedra, an edgeedge with one NHf4 trigonal pyramid, and edges with two OHf4 trigonal pyramids. In the sixth N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share corners with three OHf4 trigonal pyramids, corners with nine NHf4 trigonal pyramids, edges with two NHf4 trigonal pyramids, and edges with two OHf4 trigonal pyramids. In the seventh N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share a cornercorner with one NHf4 tetrahedra, corners with five OHf4 trigonal pyramids, corners with six NHf4 trigonal pyramids, an edgeedge with one OHf4 trigonal pyramid, and edges with three NHf4 trigonal pyramids. In the eighth N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share a cornercorner with one NHf4 tetrahedra, corners with four OHf4 trigonal pyramids, corners with seven NHf4 trigonal pyramids, an edgeedge with one OHf4 trigonal pyramid, and edges with three NHf4 trigonal pyramids. In the ninth N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share a cornercorner with one NHf4 tetrahedra, corners with four OHf4 trigonal pyramids, corners with seven NHf4 trigonal pyramids, an edgeedge with one OHf4 trigonal pyramid, and edges with three NHf4 trigonal pyramids. In the tenth N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share a cornercorner with one NHf4 tetrahedra, corners with five OHf4 trigonal pyramids, corners with six NHf4 trigonal pyramids, an edgeedge with one OHf4 trigonal pyramid, and edges with three NHf4 trigonal pyramids. In the eleventh N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share corners with five OHf4 trigonal pyramids, corners with seven NHf4 trigonal pyramids, and edges with four NHf4 trigonal pyramids. In the twelfth N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share a cornercorner with one NHf4 tetrahedra, corners with four OHf4 trigonal pyramids, corners with seven NHf4 trigonal pyramids, an edgeedge with one NHf4 trigonal pyramid, and edges with three OHf4 trigonal pyramids. In the thirteenth N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share a cornercorner with one NHf4 tetrahedra, corners with four OHf4 trigonal pyramids, corners with seven NHf4 trigonal pyramids, edges with two NHf4 trigonal pyramids, and edges with two OHf4 trigonal pyramids. In the fourteenth N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share a cornercorner with one NHf4 tetrahedra, corners with four OHf4 trigonal pyramids, corners with seven NHf4 trigonal pyramids, an edgeedge with one OHf4 trigonal pyramid, and edges with three NHf4 trigonal pyramids. In the fifteenth N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share corners with four OHf4 trigonal pyramids, corners with eight NHf4 trigonal pyramids, an edgeedge with one OHf4 trigonal pyramid, and edges with three NHf4 trigonal pyramids. In the sixteenth N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share corners with four OHf4 trigonal pyramids, corners with eight NHf4 trigonal pyramids, edges with two NHf4 trigonal pyramids, and edges with two OHf4 trigonal pyramids. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded to four Hf4+ atoms to form distorted OHf4 trigonal pyramids that share a cornercorner with one NHf4 tetrahedra, corners with three OHf4 trigonal pyramids, corners with eight NHf4 trigonal pyramids, edges with two NHf4 trigonal pyramids, and edges with two OHf4 trigonal pyramids. In the second O2- site, O2- is bonded to four Hf4+ atoms to form distorted OHf4 trigonal pyramids that share a cornercorner with one NHf4 tetrahedra, corners with five OHf4 trigonal pyramids, corners with six NHf4 trigonal pyramids, an edgeedge with one OHf4 trigonal pyramid, and edges with three NHf4 trigonal pyramids. In the third O2- site, O2- is bonded to four Hf4+ atoms to form distorted OHf4 trigonal pyramids that share corners with five OHf4 trigonal pyramids, corners with seven NHf4 trigonal pyramids, an edgeedge with one NHf4 tetrahedra, and edges with three NHf4 trigonal pyramids. In the fourth O2- site, O2- is bonded to four Hf4+ atoms to form distorted OHf4 trigonal pyramids that share corners with five O

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on KMn2O4 by Materials Project

KMn2O4 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are eight inequivalent K1+ sites. In the first K1+ site, K1+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of K–O bond distances ranging from 2.42–2.65 Å. In the second K1+ site, K1+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of K–O bond distances ranging from 2.42–2.64 Å. In the third K1+ site, K1+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of K–O bond distances ranging from 2.42–2.65 Å. In the fourth K1+ site, K1+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of K–O bond distances ranging from 2.42–2.64 Å. In the fifth K1+ site, K1+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of K–O bond distances ranging from 2.42–2.65 Å. In the sixth K1+ site, K1+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of K–O bond distances ranging from 2.42–2.65 Å. In the seventh K1+ site, K1+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of K–O bond distances ranging from 2.42–2.65 Å. In the eighth K1+ site, K1+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of K–O bond distances ranging from 2.41–2.65 Å. There are sixteen inequivalent Mn+3.50+ sites. In the first Mn+3.50+ site, Mn+3.50+ is bonded to six O2- atoms to form a mixture of distorted corner and edge-sharing MnO6 octahedra. The corner-sharing octahedra tilt angles range from 49–53°. There are a spread of Mn–O bond distances ranging from 1.92–2.32 Å. In the second Mn+3.50+ site, Mn+3.50+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing MnO6 octahedra. The corner-sharing octahedra tilt angles range from 46–50°. There are a spread of Mn–O bond distances ranging from 1.93–2.13 Å. In the third Mn+3.50+ site, Mn+3.50+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing MnO6 octahedra. The corner-sharing octahedra tilt angles range from 46–50°. There are a spread of Mn–O bond distances ranging from 1.93–2.13 Å. In the fourth Mn+3.50+ site, Mn+3.50+ is bonded to six O2- atoms to form a mixture of distorted corner and edge-sharing MnO6 octahedra. The corner-sharing octahedra tilt angles range from 50–52°. There are a spread of Mn–O bond distances ranging from 1.92–2.32 Å. In the fifth Mn+3.50+ site, Mn+3.50+ is bonded to six O2- atoms to form a mixture of distorted corner and edge-sharing MnO6 octahedra. The corner-sharing octahedra tilt angles range from 50–52°. There are a spread of Mn–O bond distances ranging from 1.92–2.34 Å. In the sixth Mn+3.50+ site, Mn+3.50+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing MnO6 octahedra. The corner-sharing octahedra tilt angles range from 46–50°. There are a spread of Mn–O bond distances ranging from 1.93–2.14 Å. In the seventh Mn+3.50+ site, Mn+3.50+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing MnO6 octahedra. The corner-sharing octahedra tilt angles range from 46–50°. There are a spread of Mn–O bond distances ranging from 1.93–2.13 Å. In the eighth Mn+3.50+ site, Mn+3.50+ is bonded to six O2- atoms to form a mixture of distorted corner and edge-sharing MnO6 octahedra. The corner-sharing octahedra tilt angles range from 50–52°. There are a spread of Mn–O bond distances ranging from 1.92–2.33 Å. In the ninth Mn+3.50+ site, Mn+3.50+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing MnO6 octahedra. The corner-sharing octahedra tilt angles range from 46–50°. There are a spread of Mn–O bond distances ranging from 1.93–2.13 Å. In the tenth Mn+3.50+ site, Mn+3.50+ is bonded to six O2- atoms to form a mixture of distorted corner and edge-sharing MnO6 octahedra. The corner-sharing octahedra tilt angles range from 50–52°. There are a spread of Mn–O bond distances ranging from 1.92–2.33 Å. In the eleventh Mn+3.50+ site, Mn+3.50+ is bonded to six O2- atoms to form a mixture of distorted corner and edge-sharing MnO6 octahedra. The corner-sharing octahedra tilt angles range from 49–52°. There are a spread of Mn–O bond distances ranging from 1.92–2.33 Å. In the twelfth Mn+3.50+ site, Mn+3.50+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing MnO6 octahedra. The corner-sharing octahedra tilt angles range from 46–50°. There are a spread of Mn–O bond distances ranging from 1.93–2.15 Å. In the thirteenth Mn+3.50+ site, Mn+3.50+ is bonded to six O2- atoms to form a mixture of distorted corner and edge-sharing MnO6 octahedra. The corner-sharing octahedra tilt angles range from 50–53°. There are a spread of Mn–O bond distances ranging from 1.92–2.34 Å. In the fourteenth Mn+3.50+ site, Mn+3.50+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing MnO6 octahedra. The corner-sharing octahedra tilt angles range from 46–50°. There are a spread of Mn–O bond distances ranging from 1.93–2.12 Å. In the fifteenth Mn+3.50+ site, Mn+3.50+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing MnO6 octahedra. The corner-sharing octahedra tilt angles range from 46–50°. There are a spread of Mn–O bond distances ranging from 1.93–2.13 Å. In the sixteenth Mn+3.50+ site, Mn+3.50+ is bonded to six O2- atoms to form a mixture of distorted corner and edge-sharing MnO6 octahedra. The corner-sharing octahedra tilt angles range from 50–52°. There are a spread of Mn–O bond distances ranging from 1.92–2.33 Å. There are thirty-two inequivalent O2- sites. In the first O2- site, O2- is bonded to one K1+ and three Mn+3.50+ atoms to form distorted OKMn3 trigonal pyramids that share corners with three OK2Mn3 trigonal bipyramids, corners with two OKMn3 trigonal pyramids, and edges with five OK2Mn3 trigonal bipyramids. In the second O2- site, O2- is bonded in a distorted trigonal planar geometry to three Mn+3.50+ atoms. In the third O2- site, O2- is bonded in a distorted trigonal planar geometry to three Mn+3.50+ atoms. In the fourth O2- site, O2- is bonded to one K1+ and three Mn+3.50+ atoms to form distorted OKMn3 trigonal pyramids that share corners with three OK2Mn3 trigonal bipyramids, corners with two OKMn3 trigonal pyramids, and edges with five OK2Mn3 trigonal bipyramids. In the fifth O2- site, O2- is bonded in a distorted trigonal planar geometry to three Mn+3.50+ atoms. In the sixth O2- site, O2- is bonded to one K1+ and three Mn+3.50+ atoms to form distorted OKMn3 trigonal pyramids that share corners with three OK2Mn3 trigonal bipyramids, corners with two OKMn3 trigonal pyramids, and edges with five OK2Mn3 trigonal bipyramids. In the seventh O2- site, O2- is bonded to one K1+ and three Mn+3.50+ atoms to form distorted OKMn3 trigonal pyramids that share corners with three OK2Mn3 trigonal bipyramids, corners with two OKMn3 trigonal pyramids, and edges with five OK2Mn3 trigonal bipyramids. In the eighth O2- site, O2- is bonded in a distorted trigonal planar geometry to three Mn+3.50+ atoms. In the ninth O2- site, O2- is bonded to one K1+ and three Mn+3.50+ atoms to form distorted OKMn3 trigonal pyramids that share corners with three OK2Mn3 trigonal bipyramids, corners with two OKMn3 trigonal pyramids, and edges with five OK2Mn3 trigonal bipyramids. In the tenth O2- site, O2- is bonded in a distorted trigonal planar geometry to three Mn+3.50+ atoms. In the eleventh O2- site, O2- is bonded in a distorted trigonal planar geometry to three Mn+3.50+ atoms. In the twelfth O2- site, O2- is bonded to one K1+ and three Mn+3.50+ atoms to form distorted OKMn3 trigonal pyramids that share corners with three OK2Mn3 trigonal bipyramids, corners with two OKMn3 trigonal pyramids, and edges with five OK2Mn3 trigonal bipyramids. In the thirteenth O2- site, O2- is bonded to one K1+ and three Mn+3.50+ atoms to form distorted OKMn3 trigonal pyramids that share corners with three OK2Mn3 trigonal bipyramids, corners with two OKMn3 trigonal pyramids, and edges with five OK2Mn3 trigonal bipyramids. In the fourteenth O2- site, O2- is bonded in a distorted trigonal planar geometry to three Mn+3.50+ atoms. In the fifteenth O2- site, O2- is bonded in a distorted trigonal planar geometry to three Mn+3.50+ atoms. In the sixteenth O2- site, O2- is bonded to one K1+ and three Mn+3.50+ atoms to form distorted OKMn3 trigonal pyramids that share corners with three OK2Mn3 trigonal bipyramids, corners with two OKMn3 trigonal pyramids, and edges with five OK2Mn3 trigonal bipyramids. In the seventeenth O2- site, O2- is bonded to two K1+ and three Mn+3.50+ atoms to form distorted OK2Mn3 trigonal bipyramids that share corners with four OK2Mn3 trigonal bipyramids, corners with three OKMn3 trigonal pyramids, edges with four OK2Mn3 trigonal bipyramids, and edges with two OKMn3 trigonal pyramids. In the eighteenth O2- site, O2- is bonded to two K1+ and three Mn+3.50+ atoms to form distorted OK2Mn3 trigonal bipyramids that share corners with four OK2Mn3 trigonal bipyramids, edges with four OK2Mn3 trigonal bipyramids, and edges with three OKMn3 trigonal pyramids. In the nineteenth O2- site, O2- is bonded to two K1+ and three Mn+3.50+ atoms to form distorted OK2Mn3 trigonal bipyramids that share corners with four OK2Mn3 trigonal bipyramids, corners with three OKMn3 trigonal pyramids, edges with four OK2Mn3 trigonal bipyramids, and edges with two OKMn3 trigonal pyramids. In the twentieth O2- site, O2- is bonded to two K1+ and three Mn+3.50+ atoms to form distorted OK2Mn3 trigonal bipyramids that share corners with four OK2Mn3 trigonal bipyramids, edges with four OK2Mn3 trigonal bipyramids, and edges with three OKMn3 trigonal pyramids. In the twenty-first O2- site, O2- is bonded to two K1+ and three Mn+3.50+ atoms to form distorted OK2Mn3 trigonal bipyramids that share corners with four OK2Mn3 trigonal bipyramids, edges with four OK2Mn3 trigonal bipyramids, and edges with three OKMn3 trigonal pyramids. In the twenty-second O2- site, O2- is bonded to two K1+ and three Mn+3.50+ atoms to form distorted OK2Mn3 trigonal bipyramids that share corners with four OK2Mn3 trigonal bipyramids, corners with three OKMn3 trigonal pyramids, edges with four OK2Mn3 trigonal bipyramids, and edges with two OKMn3 trigonal pyramids. In the twenty-third O2- site, O2- is bonded to two K1+ and three Mn+3.50+ atoms to form distorted OK2Mn3 trigonal bipyramids that share corners with four OK2Mn3 trigonal bipyramids, edges with four OK2Mn3 trigonal bipyramids, and edges with three OKMn3 trigonal pyramids. In the twenty-fourth O2- site, O2- is bonded to two K1+ and three Mn+3.50+ atoms to form distorted OK2Mn3 trigonal bipyramids that share corners with four OK2Mn3 trigonal bipyramids, corners with three OKMn3 trigonal pyramids, edges with four OK2Mn3 trigonal bipyramids, and edges with two OKMn3 trigonal pyramids. In the twenty-fifth O2- site, O2- is bonded to two K1+ and three Mn+3.50+ atoms to form distorted OK2Mn3 trigonal bipyramids that share corners with four OK2Mn3 trigonal bipyramids, edges with four OK2Mn3 trigonal bipyramids, and edges with three OKMn3 trigonal pyramids. In the twenty-sixth O2- site, O2- is bonded to two K1+ and three Mn+3.50+ atoms to form distorted OK2Mn3 trigonal bipyramids that share corners with four OK2Mn3 trigonal bipyramids, corners with three OKMn3 trigonal pyramids, edges with four OK2Mn3 trigonal bipyramids, and edges with two OKMn3 trigonal pyramids. In the twenty-seventh O2- site, O2- is bonded to two K1+ and three Mn+3.50+ atoms to form distorted OK2Mn3 trigonal bipyramids that share corners with four OK2Mn3 trigonal bipyramids, corners with three OKMn3 trigonal pyramids, edges with four OK2Mn3 trigonal bipyramids, and edges with two OKMn3 trigonal pyramids. In the twenty-eighth O2- site, O2- is bonded to two K1+ and three Mn+3.50+ atoms to form distorted OK2Mn3 trigonal bipyramids that share corners with four OK2Mn3 trigonal bipyramids, edges with four OK2Mn3 trigonal bipyramids, and

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Hf2N2O by Materials Project

Hf2ON2 is Ilmenite-like structured and crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are sixteen inequivalent Hf4+ sites. In the first Hf4+ site, Hf4+ is bonded to two N3- and four O2- atoms to form HfN2O4 octahedra that share corners with six HfN3O3 octahedra and edges with six HfN4O2 octahedra. The corner-sharing octahedra tilt angles range from 51–55°. There are one shorter (2.07 Å) and one longer (2.09 Å) Hf–N bond lengths. There are a spread of Hf–O bond distances ranging from 2.12–2.22 Å. In the second Hf4+ site, Hf4+ is bonded to three N3- and three O2- atoms to form distorted HfN3O3 octahedra that share corners with six HfN2O4 octahedra and edges with six HfN4O2 octahedra. The corner-sharing octahedra tilt angles range from 51–54°. There are one shorter (2.13 Å) and two longer (2.15 Å) Hf–N bond lengths. There are a spread of Hf–O bond distances ranging from 2.10–2.21 Å. In the third Hf4+ site, Hf4+ is bonded to four N3- and two O2- atoms to form distorted HfN4O2 octahedra that share corners with six HfN2O4 octahedra and edges with six HfN4O2 octahedra. The corner-sharing octahedra tilt angles range from 51–54°. There are a spread of Hf–N bond distances ranging from 2.13–2.22 Å. There are one shorter (2.13 Å) and one longer (2.19 Å) Hf–O bond lengths. In the fourth Hf4+ site, Hf4+ is bonded to four N3- and two O2- atoms to form distorted HfN4O2 octahedra that share corners with six HfN4O2 octahedra and edges with six HfN2O4 octahedra. The corner-sharing octahedra tilt angles range from 51–58°. There are a spread of Hf–N bond distances ranging from 2.07–2.17 Å. There are one shorter (2.31 Å) and one longer (2.38 Å) Hf–O bond lengths. In the fifth Hf4+ site, Hf4+ is bonded to four N3- and two O2- atoms to form distorted HfN4O2 octahedra that share corners with six HfN4O2 octahedra and edges with six HfN2O4 octahedra. The corner-sharing octahedra tilt angles range from 50–58°. There are a spread of Hf–N bond distances ranging from 2.09–2.30 Å. There are one shorter (2.19 Å) and one longer (2.22 Å) Hf–O bond lengths. In the sixth Hf4+ site, Hf4+ is bonded to four N3- and two O2- atoms to form HfN4O2 octahedra that share corners with six HfN3O3 octahedra and edges with six HfN4O2 octahedra. The corner-sharing octahedra tilt angles range from 52–57°. There are a spread of Hf–N bond distances ranging from 2.14–2.19 Å. There are one shorter (2.13 Å) and one longer (2.19 Å) Hf–O bond lengths. In the seventh Hf4+ site, Hf4+ is bonded to five N3- and one O2- atom to form HfN5O octahedra that share corners with six HfN4O2 octahedra and edges with six HfN3O3 octahedra. The corner-sharing octahedra tilt angles range from 54–59°. There are a spread of Hf–N bond distances ranging from 2.11–2.21 Å. The Hf–O bond length is 2.28 Å. In the eighth Hf4+ site, Hf4+ is bonded to four N3- and two O2- atoms to form distorted HfN4O2 octahedra that share corners with six HfN2O4 octahedra and edges with six HfN3O3 octahedra. The corner-sharing octahedra tilt angles range from 49–59°. There are a spread of Hf–N bond distances ranging from 2.10–2.21 Å. There are one shorter (2.20 Å) and one longer (2.27 Å) Hf–O bond lengths. In the ninth Hf4+ site, Hf4+ is bonded to four N3- and two O2- atoms to form distorted HfN4O2 octahedra that share corners with six HfN3O3 octahedra and edges with six HfN2O4 octahedra. The corner-sharing octahedra tilt angles range from 52–54°. There are a spread of Hf–N bond distances ranging from 2.08–2.18 Å. There are one shorter (2.23 Å) and one longer (2.31 Å) Hf–O bond lengths. In the tenth Hf4+ site, Hf4+ is bonded to five N3- and one O2- atom to form HfN5O octahedra that share corners with six HfN4O2 octahedra and edges with six HfN3O3 octahedra. The corner-sharing octahedra tilt angles range from 54–59°. There are a spread of Hf–N bond distances ranging from 2.11–2.22 Å. The Hf–O bond length is 2.32 Å. In the eleventh Hf4+ site, Hf4+ is bonded to three N3- and three O2- atoms to form distorted HfN3O3 octahedra that share corners with six HfN2O4 octahedra and edges with six HfN4O2 octahedra. The corner-sharing octahedra tilt angles range from 50–57°. There are a spread of Hf–N bond distances ranging from 2.10–2.21 Å. There are one shorter (2.11 Å) and two longer (2.21 Å) Hf–O bond lengths. In the twelfth Hf4+ site, Hf4+ is bonded to five N3- and one O2- atom to form distorted HfN5O octahedra that share corners with six HfN4O2 octahedra and edges with six HfN2O4 octahedra. The corner-sharing octahedra tilt angles range from 52–59°. There are a spread of Hf–N bond distances ranging from 2.10–2.20 Å. The Hf–O bond length is 2.35 Å. In the thirteenth Hf4+ site, Hf4+ is bonded to four N3- and two O2- atoms to form distorted HfN4O2 octahedra that share corners with six HfN4O2 octahedra and edges with six HfN2O4 octahedra. The corner-sharing octahedra tilt angles range from 52–57°. There are a spread of Hf–N bond distances ranging from 2.09–2.17 Å. There are one shorter (2.24 Å) and one longer (2.28 Å) Hf–O bond lengths. In the fourteenth Hf4+ site, Hf4+ is bonded to three N3- and three O2- atoms to form distorted HfN3O3 octahedra that share corners with six HfN2O4 octahedra and edges with six HfN3O3 octahedra. The corner-sharing octahedra tilt angles range from 49–57°. There are a spread of Hf–N bond distances ranging from 2.11–2.21 Å. There are a spread of Hf–O bond distances ranging from 2.13–2.21 Å. In the fifteenth Hf4+ site, Hf4+ is bonded to five N3- and one O2- atom to form distorted HfN5O octahedra that share corners with six HfN3O3 octahedra and edges with six HfN2O4 octahedra. The corner-sharing octahedra tilt angles range from 51–58°. There are a spread of Hf–N bond distances ranging from 2.13–2.24 Å. The Hf–O bond length is 2.23 Å. In the sixteenth Hf4+ site, Hf4+ is bonded to five N3- and one O2- atom to form distorted HfN5O octahedra that share corners with six HfN2O4 octahedra and edges with six HfN4O2 octahedra. The corner-sharing octahedra tilt angles range from 51–56°. There are a spread of Hf–N bond distances ranging from 2.12–2.26 Å. The Hf–O bond length is 2.21 Å. There are sixteen inequivalent N3- sites. In the first N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share a cornercorner with one NHf4 tetrahedra, corners with four OHf4 trigonal pyramids, corners with seven NHf4 trigonal pyramids, an edgeedge with one NHf4 trigonal pyramid, and edges with three OHf4 trigonal pyramids. In the second N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 tetrahedra that share corners with three OHf4 trigonal pyramids, corners with nine NHf4 trigonal pyramids, an edgeedge with one NHf4 trigonal pyramid, and edges with three OHf4 trigonal pyramids. In the third N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share a cornercorner with one NHf4 tetrahedra, corners with three OHf4 trigonal pyramids, corners with eight NHf4 trigonal pyramids, edges with two NHf4 trigonal pyramids, and edges with two OHf4 trigonal pyramids. In the fourth N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share corners with four OHf4 trigonal pyramids, corners with eight NHf4 trigonal pyramids, edges with two NHf4 trigonal pyramids, and edges with two OHf4 trigonal pyramids. In the fifth N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share corners with four OHf4 trigonal pyramids, corners with eight NHf4 trigonal pyramids, an edgeedge with one NHf4 tetrahedra, an edgeedge with one NHf4 trigonal pyramid, and edges with two OHf4 trigonal pyramids. In the sixth N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share corners with four OHf4 trigonal pyramids, corners with eight NHf4 trigonal pyramids, edges with two NHf4 trigonal pyramids, and edges with two OHf4 trigonal pyramids. In the seventh N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share a cornercorner with one NHf4 tetrahedra, corners with four OHf4 trigonal pyramids, corners with seven NHf4 trigonal pyramids, an edgeedge with one OHf4 trigonal pyramid, and edges with three NHf4 trigonal pyramids. In the eighth N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share a cornercorner with one NHf4 tetrahedra, corners with four OHf4 trigonal pyramids, corners with seven NHf4 trigonal pyramids, an edgeedge with one OHf4 trigonal pyramid, and edges with three NHf4 trigonal pyramids. In the ninth N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share a cornercorner with one NHf4 tetrahedra, corners with four OHf4 trigonal pyramids, corners with seven NHf4 trigonal pyramids, edges with two NHf4 trigonal pyramids, and edges with two OHf4 trigonal pyramids. In the tenth N3- site, N3- is bonded to four Hf4+ atoms to form NHf4 trigonal pyramids that share corners with five OHf4 trigonal pyramids, corners with seven NHf4 trigonal pyramids, and edges with four NHf4 trigonal pyramids. In the eleventh N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share a cornercorner with one NHf4 tetrahedra, corners with four OHf4 trigonal pyramids, corners with seven NHf4 trigonal pyramids, edges with two NHf4 trigonal pyramids, and edges with two OHf4 trigonal pyramids. In the twelfth N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share a cornercorner with one NHf4 tetrahedra, corners with five OHf4 trigonal pyramids, corners with six NHf4 trigonal pyramids, an edgeedge with one OHf4 trigonal pyramid, and edges with three NHf4 trigonal pyramids. In the thirteenth N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share a cornercorner with one NHf4 tetrahedra, corners with four OHf4 trigonal pyramids, corners with seven NHf4 trigonal pyramids, an edgeedge with one OHf4 trigonal pyramid, and edges with three NHf4 trigonal pyramids. In the fourteenth N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share a cornercorner with one NHf4 tetrahedra, corners with five OHf4 trigonal pyramids, corners with six NHf4 trigonal pyramids, an edgeedge with one OHf4 trigonal pyramid, and edges with three NHf4 trigonal pyramids. In the fifteenth N3- site, N3- is bonded to four Hf4+ atoms to form NHf4 trigonal pyramids that share corners with four OHf4 trigonal pyramids, corners with eight NHf4 trigonal pyramids, an edgeedge with one OHf4 trigonal pyramid, and edges with three NHf4 trigonal pyramids. In the sixteenth N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share corners with three OHf4 trigonal pyramids, corners with nine NHf4 trigonal pyramids, edges with two NHf4 trigonal pyramids, and edges with two OHf4 trigonal pyramids. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded to four Hf4+ atoms to form distorted OHf4 trigonal pyramids that share a cornercorner with one NHf4 tetrahedra, corners with three OHf4 trigonal pyramids, corners with eight NHf4 trigonal pyramids, edges with two NHf4 trigonal pyramids, and edges with two OHf4 trigonal pyramids. In the second O2- site, O2- is bonded to four Hf4+ atoms to form distorted OHf4 trigonal pyramids that share corners with five OHf4 trigonal pyramids, corners with seven NHf4 trigonal pyramids, an edgeedge with one NHf4 tetrahedra, an edgeedge with one OHf4 trigonal pyramid, and edges with two NHf4 trigonal pyramids. In the third O2- site, O2- is bonded to four Hf4+ atoms to form distorted OHf4 trigonal pyramids that share corners with five OHf4 trigonal pyramids, corners with seven NHf4 trigonal pyramids, and edges with four NHf4 trigonal pyramids. In the fourth O2- site, O2- is bonded to four Hf4+ a

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ti2N2O by Materials Project

Ti2N2O is Ilmenite-like structured and crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are sixteen inequivalent Ti4+ sites. In the first Ti4+ site, Ti4+ is bonded to three N3- and three O2- atoms to form TiN3O3 octahedra that share corners with five TiN3O3 octahedra, a cornercorner with one TiN2O4 pentagonal pyramid, and edges with six TiN4O2 octahedra. The corner-sharing octahedra tilt angles range from 49–55°. There are a spread of Ti–N bond distances ranging from 1.96–1.99 Å. There are one shorter (2.08 Å) and two longer (2.11 Å) Ti–O bond lengths. In the second Ti4+ site, Ti4+ is bonded to two N3- and four O2- atoms to form distorted TiN2O4 pentagonal pyramids that share corners with six TiN3O3 octahedra and edges with six TiN4O2 octahedra. The corner-sharing octahedra tilt angles range from 46–55°. There is one shorter (1.94 Å) and one longer (1.99 Å) Ti–N bond length. There are a spread of Ti–O bond distances ranging from 1.97–2.12 Å. In the third Ti4+ site, Ti4+ is bonded to three N3- and three O2- atoms to form distorted TiN3O3 octahedra that share corners with five TiN3O3 octahedra, a cornercorner with one TiN2O4 pentagonal pyramid, and edges with six TiN5O octahedra. The corner-sharing octahedra tilt angles range from 49–52°. There are a spread of Ti–N bond distances ranging from 1.99–2.03 Å. There are a spread of Ti–O bond distances ranging from 2.02–2.11 Å. In the fourth Ti4+ site, Ti4+ is bonded to four N3- and two O2- atoms to form distorted TiN4O2 octahedra that share corners with six TiN5O octahedra, edges with five TiN3O3 octahedra, and an edgeedge with one TiN2O4 pentagonal pyramid. The corner-sharing octahedra tilt angles range from 51–56°. There are a spread of Ti–N bond distances ranging from 1.98–2.07 Å. There are one shorter (2.09 Å) and one longer (2.15 Å) Ti–O bond lengths. In the fifth Ti4+ site, Ti4+ is bonded to four N3- and two O2- atoms to form a mixture of distorted corner and edge-sharing TiN4O2 octahedra. The corner-sharing octahedra tilt angles range from 49–54°. There are a spread of Ti–N bond distances ranging from 1.99–2.13 Å. There are one shorter (2.08 Å) and one longer (2.11 Å) Ti–O bond lengths. In the sixth Ti4+ site, Ti4+ is bonded to five N3- and one O2- atom to form TiN5O octahedra that share corners with six TiN4O2 octahedra, edges with five TiN3O3 octahedra, and an edgeedge with one TiN2O4 pentagonal pyramid. The corner-sharing octahedra tilt angles range from 51–56°. There are a spread of Ti–N bond distances ranging from 1.98–2.09 Å. The Ti–O bond length is 2.15 Å. In the seventh Ti4+ site, Ti4+ is bonded to four N3- and two O2- atoms to form distorted TiN4O2 octahedra that share corners with five TiN3O3 octahedra, a cornercorner with one TiN2O4 pentagonal pyramid, and edges with six TiN3O3 octahedra. The corner-sharing octahedra tilt angles range from 49–52°. There are a spread of Ti–N bond distances ranging from 1.97–2.10 Å. There are one shorter (2.10 Å) and one longer (2.14 Å) Ti–O bond lengths. In the eighth Ti4+ site, Ti4+ is bonded to four N3- and two O2- atoms to form TiN4O2 octahedra that share corners with six TiN3O3 octahedra, edges with five TiN4O2 octahedra, and an edgeedge with one TiN2O4 pentagonal pyramid. The corner-sharing octahedra tilt angles range from 50–55°. There are a spread of Ti–N bond distances ranging from 1.96–2.09 Å. There are one shorter (2.11 Å) and one longer (2.14 Å) Ti–O bond lengths. In the ninth Ti4+ site, Ti4+ is bonded to three N3- and three O2- atoms to form distorted TiN3O3 octahedra that share corners with five TiN3O3 octahedra, a cornercorner with one TiN2O4 pentagonal pyramid, and edges with six TiN4O2 octahedra. The corner-sharing octahedra tilt angles range from 49–52°. There are a spread of Ti–N bond distances ranging from 1.98–2.05 Å. There are a spread of Ti–O bond distances ranging from 2.02–2.07 Å. In the tenth Ti4+ site, Ti4+ is bonded to four N3- and two O2- atoms to form TiN4O2 octahedra that share corners with five TiN4O2 octahedra, a cornercorner with one TiN2O4 pentagonal pyramid, and edges with six TiN3O3 octahedra. The corner-sharing octahedra tilt angles range from 50–56°. There are a spread of Ti–N bond distances ranging from 1.95–2.07 Å. There are one shorter (2.08 Å) and one longer (2.15 Å) Ti–O bond lengths. In the eleventh Ti4+ site, Ti4+ is bonded to four N3- and two O2- atoms to form distorted TiN4O2 octahedra that share corners with six TiN3O3 octahedra, edges with five TiN3O3 octahedra, and an edgeedge with one TiN2O4 pentagonal pyramid. The corner-sharing octahedra tilt angles range from 52–56°. There are a spread of Ti–N bond distances ranging from 1.96–2.08 Å. There are one shorter (2.10 Å) and one longer (2.14 Å) Ti–O bond lengths. In the twelfth Ti4+ site, Ti4+ is bonded to five N3- and one O2- atom to form distorted TiN5O octahedra that share corners with six TiN4O2 octahedra, edges with five TiN3O3 octahedra, and an edgeedge with one TiN2O4 pentagonal pyramid. The corner-sharing octahedra tilt angles range from 52–56°. There are a spread of Ti–N bond distances ranging from 2.00–2.07 Å. The Ti–O bond length is 2.15 Å. In the thirteenth Ti4+ site, Ti4+ is bonded to four N3- and two O2- atoms to form distorted TiN4O2 octahedra that share corners with six TiN4O2 octahedra and edges with six TiN3O3 octahedra. The corner-sharing octahedra tilt angles range from 52–55°. There are a spread of Ti–N bond distances ranging from 2.01–2.08 Å. There are one shorter (2.07 Å) and one longer (2.09 Å) Ti–O bond lengths. In the fourteenth Ti4+ site, Ti4+ is bonded to four N3- and two O2- atoms to form distorted TiN4O2 octahedra that share corners with six TiN3O3 octahedra, edges with five TiN4O2 octahedra, and an edgeedge with one TiN2O4 pentagonal pyramid. The corner-sharing octahedra tilt angles range from 52–55°. There are a spread of Ti–N bond distances ranging from 1.99–2.06 Å. There are one shorter (2.09 Å) and one longer (2.12 Å) Ti–O bond lengths. In the fifteenth Ti4+ site, Ti4+ is bonded to five N3- and one O2- atom to form distorted TiN5O octahedra that share corners with five TiN4O2 octahedra, a cornercorner with one TiN2O4 pentagonal pyramid, and edges with six TiN3O3 octahedra. The corner-sharing octahedra tilt angles range from 49–55°. There are a spread of Ti–N bond distances ranging from 2.00–2.07 Å. The Ti–O bond length is 2.11 Å. In the sixteenth Ti4+ site, Ti4+ is bonded to six N3- atoms to form a mixture of distorted corner and edge-sharing TiN6 octahedra. The corner-sharing octahedra tilt angles range from 52–55°. There are a spread of Ti–N bond distances ranging from 2.03–2.11 Å. There are sixteen inequivalent N3- sites. In the first N3- site, N3- is bonded to four Ti4+ atoms to form distorted NTi4 trigonal pyramids that share corners with three OTi4 trigonal pyramids, corners with nine NTi4 trigonal pyramids, an edgeedge with one NTi4 trigonal pyramid, and edges with three OTi4 trigonal pyramids. In the second N3- site, N3- is bonded to four Ti4+ atoms to form distorted NTi4 trigonal pyramids that share corners with three OTi4 trigonal pyramids, corners with nine NTi4 trigonal pyramids, an edgeedge with one NTi4 trigonal pyramid, and edges with three OTi4 trigonal pyramids. In the third N3- site, N3- is bonded to four Ti4+ atoms to form distorted NTi4 trigonal pyramids that share a cornercorner with one OTi4 trigonal pyramid, corners with eleven NTi4 trigonal pyramids, and edges with four OTi4 trigonal pyramids. In the fourth N3- site, N3- is bonded to four Ti4+ atoms to form distorted NTi4 trigonal pyramids that share corners with three OTi4 trigonal pyramids, corners with nine NTi4 trigonal pyramids, edges with two NTi4 trigonal pyramids, and edges with two OTi4 trigonal pyramids. In the fifth N3- site, N3- is bonded to four Ti4+ atoms to form distorted NTi4 trigonal pyramids that share corners with three OTi4 trigonal pyramids, corners with nine NTi4 trigonal pyramids, an edgeedge with one NTi4 trigonal pyramid, and edges with three OTi4 trigonal pyramids. In the sixth N3- site, N3- is bonded to four Ti4+ atoms to form distorted NTi4 trigonal pyramids that share corners with five OTi4 trigonal pyramids, corners with seven NTi4 trigonal pyramids, an edgeedge with one OTi4 trigonal pyramid, and edges with three NTi4 trigonal pyramids. In the seventh N3- site, N3- is bonded to four Ti4+ atoms to form distorted NTi4 trigonal pyramids that share corners with five NTi4 trigonal pyramids, corners with seven OTi4 trigonal pyramids, and edges with four NTi4 trigonal pyramids. In the eighth N3- site, N3- is bonded to four Ti4+ atoms to form distorted NTi4 trigonal pyramids that share corners with five OTi4 trigonal pyramids, corners with seven NTi4 trigonal pyramids, and edges with four NTi4 trigonal pyramids. In the ninth N3- site, N3- is bonded to four Ti4+ atoms to form NTi4 trigonal pyramids that share corners with three OTi4 trigonal pyramids, corners with nine NTi4 trigonal pyramids, edges with two NTi4 trigonal pyramids, and edges with two OTi4 trigonal pyramids. In the tenth N3- site, N3- is bonded to four Ti4+ atoms to form distorted NTi4 trigonal pyramids that share corners with three OTi4 trigonal pyramids, corners with nine NTi4 trigonal pyramids, edges with two NTi4 trigonal pyramids, and edges with two OTi4 trigonal pyramids. In the eleventh N3- site, N3- is bonded to four Ti4+ atoms to form distorted NTi4 trigonal pyramids that share corners with three OTi4 trigonal pyramids, corners with nine NTi4 trigonal pyramids, an edgeedge with one OTi4 trigonal pyramid, and edges with three NTi4 trigonal pyramids. In the twelfth N3- site, N3- is bonded to four Ti4+ atoms to form distorted NTi4 trigonal pyramids that share corners with three OTi4 trigonal pyramids, corners with nine NTi4 trigonal pyramids, edges with two NTi4 trigonal pyramids, and edges with two OTi4 trigonal pyramids. In the thirteenth N3- site, N3- is bonded to four Ti4+ atoms to form NTi4 trigonal pyramids that share corners with three OTi4 trigonal pyramids, corners with nine NTi4 trigonal pyramids, edges with two NTi4 trigonal pyramids, and edges with two OTi4 trigonal pyramids. In the fourteenth N3- site, N3- is bonded to four Ti4+ atoms to form NTi4 trigonal pyramids that share corners with five NTi4 trigonal pyramids, corners with seven OTi4 trigonal pyramids, and edges with four NTi4 trigonal pyramids. In the fifteenth N3- site, N3- is bonded to four Ti4+ atoms to form NTi4 trigonal pyramids that share corners with five OTi4 trigonal pyramids, corners with seven NTi4 trigonal pyramids, an edgeedge with one OTi4 trigonal pyramid, and edges with three NTi4 trigonal pyramids. In the sixteenth N3- site, N3- is bonded to four Ti4+ atoms to form NTi4 trigonal pyramids that share a cornercorner with one OTi4 trigonal pyramid, corners with eleven NTi4 trigonal pyramids, edges with two NTi4 trigonal pyramids, and edges with two OTi4 trigonal pyramids. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded to four Ti4+ atoms to form OTi4 trigonal pyramids that share corners with five OTi4 trigonal pyramids, corners with seven NTi4 trigonal pyramids, an edgeedge with one OTi4 trigonal pyramid, and edges with three NTi4 trigonal pyramids. In the second O2- site, O2- is bonded to four Ti4+ atoms to form OTi4 trigonal pyramids that share corners with five OTi4 trigonal pyramids, corners with seven NTi4 trigonal pyramids, and edges with four NTi4 trigonal pyramids. In the third O2- site, O2- is bonded to four Ti4+ atoms to form OTi4 trigonal pyramids that share corners with five NTi4 trigonal pyramids, corners with seven OTi4 trigonal pyramids, and edges with four NTi4 trigonal pyramids. In the fourth O2- site, O2- is bonded to four Ti4+ atoms to form distorted OTi4 trigonal pyramids that share corners with five OTi4 trigonal pyramids, corners with seven NTi4 trigonal pyramids, an edgeedge with one OT

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Hf2N2O by Materials Project

Hf2ON2 is Ilmenite-like structured and crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are sixteen inequivalent Hf4+ sites. In the first Hf4+ site, Hf4+ is bonded to three N3- and three O2- atoms to form HfN3O3 octahedra that share corners with six HfN2O4 octahedra and edges with six HfN3O3 octahedra. The corner-sharing octahedra tilt angles range from 50–56°. There are a spread of Hf–N bond distances ranging from 2.09–2.13 Å. There are one shorter (2.19 Å) and two longer (2.23 Å) Hf–O bond lengths. In the second Hf4+ site, Hf4+ is bonded to two N3- and four O2- atoms to form a mixture of distorted corner and edge-sharing HfN2O4 octahedra. The corner-sharing octahedra tilt angles range from 50–53°. There are one shorter (2.11 Å) and one longer (2.14 Å) Hf–N bond lengths. There are a spread of Hf–O bond distances ranging from 2.09–2.20 Å. In the third Hf4+ site, Hf4+ is bonded to four N3- and two O2- atoms to form distorted HfN4O2 octahedra that share corners with six HfN3O3 octahedra and edges with six HfN5O octahedra. The corner-sharing octahedra tilt angles range from 51–57°. There are a spread of Hf–N bond distances ranging from 2.14–2.22 Å. There are one shorter (2.13 Å) and one longer (2.21 Å) Hf–O bond lengths. In the fourth Hf4+ site, Hf4+ is bonded to three N3- and three O2- atoms to form distorted HfN3O3 octahedra that share corners with six HfN5O octahedra and edges with six HfN3O3 octahedra. The corner-sharing octahedra tilt angles range from 51–56°. There are a spread of Hf–N bond distances ranging from 2.07–2.11 Å. There are a spread of Hf–O bond distances ranging from 2.19–2.30 Å. In the fifth Hf4+ site, Hf4+ is bonded to four N3- and two O2- atoms to form distorted HfN4O2 octahedra that share corners with six HfN4O2 octahedra and edges with six HfN3O3 octahedra. The corner-sharing octahedra tilt angles range from 51–55°. There are a spread of Hf–N bond distances ranging from 2.09–2.29 Å. Both Hf–O bond lengths are 2.21 Å. In the sixth Hf4+ site, Hf4+ is bonded to five N3- and one O2- atom to form HfN5O octahedra that share corners with six HfN3O3 octahedra and edges with six HfN2O4 octahedra. The corner-sharing octahedra tilt angles range from 54–60°. There are a spread of Hf–N bond distances ranging from 2.10–2.20 Å. The Hf–O bond length is 2.33 Å. In the seventh Hf4+ site, Hf4+ is bonded to four N3- and two O2- atoms to form HfN4O2 octahedra that share corners with six HfN2O4 octahedra and edges with six HfN4O2 octahedra. The corner-sharing octahedra tilt angles range from 53–56°. There are a spread of Hf–N bond distances ranging from 2.13–2.20 Å. There are one shorter (2.15 Å) and one longer (2.20 Å) Hf–O bond lengths. In the eighth Hf4+ site, Hf4+ is bonded to four N3- and two O2- atoms to form HfN4O2 octahedra that share corners with six HfN4O2 octahedra and edges with six HfN2O4 octahedra. The corner-sharing octahedra tilt angles range from 54–59°. There are a spread of Hf–N bond distances ranging from 2.08–2.17 Å. There are one shorter (2.27 Å) and one longer (2.29 Å) Hf–O bond lengths. In the ninth Hf4+ site, Hf4+ is bonded to three N3- and three O2- atoms to form a mixture of distorted corner and edge-sharing HfN3O3 octahedra. The corner-sharing octahedra tilt angles range from 50–55°. There are two shorter (2.11 Å) and one longer (2.19 Å) Hf–N bond lengths. There are a spread of Hf–O bond distances ranging from 2.13–2.20 Å. In the tenth Hf4+ site, Hf4+ is bonded to five N3- and one O2- atom to form distorted HfN5O octahedra that share corners with six HfN2O4 octahedra and edges with six HfN3O3 octahedra. The corner-sharing octahedra tilt angles range from 51–55°. There are a spread of Hf–N bond distances ranging from 2.11–2.21 Å. The Hf–O bond length is 2.27 Å. In the eleventh Hf4+ site, Hf4+ is bonded to four N3- and two O2- atoms to form distorted HfN4O2 octahedra that share corners with six HfN3O3 octahedra and edges with six HfN2O4 octahedra. The corner-sharing octahedra tilt angles range from 49–60°. There are a spread of Hf–N bond distances ranging from 2.10–2.24 Å. There are one shorter (2.21 Å) and one longer (2.24 Å) Hf–O bond lengths. In the twelfth Hf4+ site, Hf4+ is bonded to four N3- and two O2- atoms to form a mixture of distorted corner and edge-sharing HfN4O2 octahedra. The corner-sharing octahedra tilt angles range from 52–59°. There are a spread of Hf–N bond distances ranging from 2.13–2.21 Å. There are one shorter (2.16 Å) and one longer (2.24 Å) Hf–O bond lengths. In the thirteenth Hf4+ site, Hf4+ is bonded to five N3- and one O2- atom to form a mixture of distorted corner and edge-sharing HfN5O octahedra. The corner-sharing octahedra tilt angles range from 52–57°. There are a spread of Hf–N bond distances ranging from 2.10–2.20 Å. The Hf–O bond length is 2.31 Å. In the fourteenth Hf4+ site, Hf4+ is bonded to four N3- and two O2- atoms to form distorted HfN4O2 octahedra that share corners with six HfN3O3 octahedra and edges with six HfN2O4 octahedra. The corner-sharing octahedra tilt angles range from 49–57°. There are a spread of Hf–N bond distances ranging from 2.08–2.21 Å. There are one shorter (2.17 Å) and one longer (2.33 Å) Hf–O bond lengths. In the fifteenth Hf4+ site, Hf4+ is bonded to five N3- and one O2- atom to form distorted HfN5O octahedra that share corners with six HfN2O4 octahedra and edges with six HfN3O3 octahedra. The corner-sharing octahedra tilt angles range from 52–59°. There are a spread of Hf–N bond distances ranging from 2.13–2.24 Å. The Hf–O bond length is 2.21 Å. In the sixteenth Hf4+ site, Hf4+ is bonded to five N3- and one O2- atom to form distorted HfN5O octahedra that share corners with six HfN3O3 octahedra and edges with six HfN4O2 octahedra. The corner-sharing octahedra tilt angles range from 51–56°. There are a spread of Hf–N bond distances ranging from 2.14–2.25 Å. The Hf–O bond length is 2.20 Å. There are sixteen inequivalent N3- sites. In the first N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share corners with two NHf4 tetrahedra, corners with three OHf4 trigonal pyramids, corners with seven NHf4 trigonal pyramids, edges with two NHf4 trigonal pyramids, and edges with two OHf4 trigonal pyramids. In the second N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share a cornercorner with one NHf4 tetrahedra, corners with four OHf4 trigonal pyramids, corners with seven NHf4 trigonal pyramids, an edgeedge with one NHf4 trigonal pyramid, and edges with three OHf4 trigonal pyramids. In the third N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 tetrahedra that share a cornercorner with one NHf4 tetrahedra, corners with three OHf4 trigonal pyramids, corners with eight NHf4 trigonal pyramids, an edgeedge with one NHf4 trigonal pyramid, and edges with three OHf4 trigonal pyramids. In the fourth N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share a cornercorner with one NHf4 tetrahedra, corners with four OHf4 trigonal pyramids, corners with seven NHf4 trigonal pyramids, an edgeedge with one NHf4 trigonal pyramid, and edges with three OHf4 trigonal pyramids. In the fifth N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share corners with four OHf4 trigonal pyramids, corners with eight NHf4 trigonal pyramids, an edgeedge with one NHf4 tetrahedra, an edgeedge with one OHf4 trigonal pyramid, and edges with two NHf4 trigonal pyramids. In the sixth N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share a cornercorner with one NHf4 tetrahedra, corners with four OHf4 trigonal pyramids, corners with seven NHf4 trigonal pyramids, an edgeedge with one OHf4 trigonal pyramid, and edges with three NHf4 trigonal pyramids. In the seventh N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 tetrahedra that share a cornercorner with one NHf4 tetrahedra, corners with four OHf4 trigonal pyramids, corners with seven NHf4 trigonal pyramids, edges with two NHf4 trigonal pyramids, and edges with two OHf4 trigonal pyramids. In the eighth N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share corners with five OHf4 trigonal pyramids, corners with seven NHf4 trigonal pyramids, an edgeedge with one NHf4 tetrahedra, and edges with three NHf4 trigonal pyramids. In the ninth N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share a cornercorner with one NHf4 tetrahedra, corners with four OHf4 trigonal pyramids, corners with seven NHf4 trigonal pyramids, an edgeedge with one OHf4 trigonal pyramid, and edges with three NHf4 trigonal pyramids. In the tenth N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share corners with two NHf4 tetrahedra, corners with four OHf4 trigonal pyramids, corners with six NHf4 trigonal pyramids, edges with two NHf4 trigonal pyramids, and edges with two OHf4 trigonal pyramids. In the eleventh N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share a cornercorner with one NHf4 tetrahedra, corners with five OHf4 trigonal pyramids, corners with six NHf4 trigonal pyramids, an edgeedge with one OHf4 trigonal pyramid, and edges with three NHf4 trigonal pyramids. In the twelfth N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share corners with two NHf4 tetrahedra, corners with four OHf4 trigonal pyramids, corners with six NHf4 trigonal pyramids, an edgeedge with one OHf4 trigonal pyramid, and edges with three NHf4 trigonal pyramids. In the thirteenth N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share corners with two NHf4 tetrahedra, corners with four OHf4 trigonal pyramids, corners with six NHf4 trigonal pyramids, an edgeedge with one OHf4 trigonal pyramid, and edges with three NHf4 trigonal pyramids. In the fourteenth N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share a cornercorner with one NHf4 tetrahedra, corners with five OHf4 trigonal pyramids, corners with six NHf4 trigonal pyramids, an edgeedge with one NHf4 tetrahedra, an edgeedge with one OHf4 trigonal pyramid, and edges with two NHf4 trigonal pyramids. In the fifteenth N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share corners with four OHf4 trigonal pyramids, corners with eight NHf4 trigonal pyramids, edges with two NHf4 trigonal pyramids, and edges with two OHf4 trigonal pyramids. In the sixteenth N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share a cornercorner with one NHf4 tetrahedra, corners with three OHf4 trigonal pyramids, corners with eight NHf4 trigonal pyramids, edges with two NHf4 trigonal pyramids, and edges with two OHf4 trigonal pyramids. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded to four Hf4+ atoms to form distorted OHf4 trigonal pyramids that share corners with five OHf4 trigonal pyramids, corners with seven NHf4 trigonal pyramids, edges with two NHf4 tetrahedra, an edgeedge with one NHf4 trigonal pyramid, and an edgeedge with one OHf4 trigonal pyramid. In the second O2- site, O2- is bonded to four Hf4+ atoms to form distorted OHf4 trigonal pyramids that share corners with five OHf4 trigonal pyramids, corners with seven NHf4 trigonal pyramids, and edges with four NHf4 trigonal pyramids. In the third O2- site, O2- is bonded to four Hf4+ atoms to form distorted OHf4 trigonal pyramids that share a cornercorner with one NHf4 tetrahedra, corners with five OHf4 trigonal pyramids, corners with six NHf4 trigonal pyramids, an edgeedge with one OHf4 trigonal pyramid, and edges with three NHf4 trigonal pyramids. In the fourth O2- site, O2- is bond

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Hf2N2O by Materials Project

Hf2ON2 is Ilmenite-like structured and crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are sixteen inequivalent Hf4+ sites. In the first Hf4+ site, Hf4+ is bonded to three N3- and three O2- atoms to form distorted HfN3O3 octahedra that share corners with six HfN3O3 octahedra and edges with six HfN4O2 octahedra. The corner-sharing octahedra tilt angles range from 52–57°. There are two shorter (2.11 Å) and one longer (2.22 Å) Hf–N bond lengths. There are a spread of Hf–O bond distances ranging from 2.14–2.22 Å. In the second Hf4+ site, Hf4+ is bonded to four N3- and two O2- atoms to form a mixture of distorted edge and corner-sharing HfN4O2 octahedra. The corner-sharing octahedra tilt angles range from 53–60°. There are a spread of Hf–N bond distances ranging from 2.09–2.23 Å. There are one shorter (2.20 Å) and one longer (2.27 Å) Hf–O bond lengths. In the third Hf4+ site, Hf4+ is bonded to four N3- and two O2- atoms to form a mixture of edge and corner-sharing HfN4O2 octahedra. The corner-sharing octahedra tilt angles range from 51–59°. There are a spread of Hf–N bond distances ranging from 2.09–2.16 Å. Both Hf–O bond lengths are 2.26 Å. In the fourth Hf4+ site, Hf4+ is bonded to three N3- and three O2- atoms to form a mixture of distorted edge and corner-sharing HfN3O3 octahedra. The corner-sharing octahedra tilt angles range from 51–57°. There are one shorter (2.07 Å) and two longer (2.10 Å) Hf–N bond lengths. There are a spread of Hf–O bond distances ranging from 2.20–2.29 Å. In the fifth Hf4+ site, Hf4+ is bonded to three N3- and three O2- atoms to form HfN3O3 octahedra that share corners with six HfN4O2 octahedra and edges with six HfN3O3 octahedra. The corner-sharing octahedra tilt angles range from 53–60°. There are a spread of Hf–N bond distances ranging from 2.07–2.18 Å. There are a spread of Hf–O bond distances ranging from 2.15–2.26 Å. In the sixth Hf4+ site, Hf4+ is bonded to four N3- and two O2- atoms to form HfN4O2 octahedra that share corners with six HfN3O3 octahedra and edges with six HfN4O2 octahedra. The corner-sharing octahedra tilt angles range from 52–57°. There are a spread of Hf–N bond distances ranging from 2.15–2.18 Å. There are one shorter (2.15 Å) and one longer (2.19 Å) Hf–O bond lengths. In the seventh Hf4+ site, Hf4+ is bonded to four N3- and two O2- atoms to form a mixture of distorted edge and corner-sharing HfN4O2 octahedra. The corner-sharing octahedra tilt angles range from 50–56°. There are a spread of Hf–N bond distances ranging from 2.14–2.19 Å. Both Hf–O bond lengths are 2.16 Å. In the eighth Hf4+ site, Hf4+ is bonded to four N3- and two O2- atoms to form distorted HfN4O2 octahedra that share corners with six HfN3O3 octahedra and edges with six HfN4O2 octahedra. The corner-sharing octahedra tilt angles range from 50–55°. There are a spread of Hf–N bond distances ranging from 2.07–2.17 Å. There are one shorter (2.21 Å) and one longer (2.29 Å) Hf–O bond lengths. In the ninth Hf4+ site, Hf4+ is bonded to three N3- and three O2- atoms to form distorted HfN3O3 octahedra that share corners with six HfN4O2 octahedra and edges with six HfN3O3 octahedra. The corner-sharing octahedra tilt angles range from 51–56°. There are one shorter (2.08 Å) and two longer (2.13 Å) Hf–N bond lengths. There are a spread of Hf–O bond distances ranging from 2.10–2.29 Å. In the tenth Hf4+ site, Hf4+ is bonded to four N3- and two O2- atoms to form distorted HfN4O2 octahedra that share corners with six HfN4O2 octahedra and edges with six HfN3O3 octahedra. The corner-sharing octahedra tilt angles range from 53–55°. There are a spread of Hf–N bond distances ranging from 2.12–2.26 Å. There are one shorter (2.13 Å) and one longer (2.25 Å) Hf–O bond lengths. In the eleventh Hf4+ site, Hf4+ is bonded to five N3- and one O2- atom to form distorted HfN5O octahedra that share corners with six HfN3O3 octahedra and edges with six HfN4O2 octahedra. The corner-sharing octahedra tilt angles range from 52–55°. There are a spread of Hf–N bond distances ranging from 2.14–2.26 Å. The Hf–O bond length is 2.19 Å. In the twelfth Hf4+ site, Hf4+ is bonded to five N3- and one O2- atom to form distorted HfN5O octahedra that share corners with six HfN4O2 octahedra and edges with six HfN3O3 octahedra. The corner-sharing octahedra tilt angles range from 51–57°. There are a spread of Hf–N bond distances ranging from 2.13–2.20 Å. The Hf–O bond length is 2.26 Å. In the thirteenth Hf4+ site, Hf4+ is bonded to five N3- and one O2- atom to form a mixture of edge and corner-sharing HfN5O octahedra. The corner-sharing octahedra tilt angles range from 54–57°. There are a spread of Hf–N bond distances ranging from 2.10–2.23 Å. The Hf–O bond length is 2.29 Å. In the fourteenth Hf4+ site, Hf4+ is bonded to four N3- and two O2- atoms to form distorted HfN4O2 octahedra that share corners with six HfN3O3 octahedra and edges with six HfN4O2 octahedra. The corner-sharing octahedra tilt angles range from 53–55°. There are a spread of Hf–N bond distances ranging from 2.11–2.26 Å. Both Hf–O bond lengths are 2.16 Å. In the fifteenth Hf4+ site, Hf4+ is bonded to five N3- and one O2- atom to form distorted HfN5O octahedra that share corners with six HfN4O2 octahedra and edges with six HfN3O3 octahedra. The corner-sharing octahedra tilt angles range from 51–59°. There are a spread of Hf–N bond distances ranging from 2.09–2.24 Å. The Hf–O bond length is 2.33 Å. In the sixteenth Hf4+ site, Hf4+ is bonded to four N3- and two O2- atoms to form a mixture of distorted edge and corner-sharing HfN4O2 octahedra. The corner-sharing octahedra tilt angles range from 51–55°. There are a spread of Hf–N bond distances ranging from 2.12–2.22 Å. There are one shorter (2.22 Å) and one longer (2.25 Å) Hf–O bond lengths. There are sixteen inequivalent N3- sites. In the first N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 tetrahedra that share corners with two OHf4 trigonal pyramids, corners with nine NHf4 trigonal pyramids, an edgeedge with one NHf4 trigonal pyramid, and edges with three OHf4 trigonal pyramids. In the second N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share corners with five OHf4 trigonal pyramids, corners with six NHf4 trigonal pyramids, an edgeedge with one NHf4 tetrahedra, an edgeedge with one NHf4 trigonal pyramid, and edges with two OHf4 trigonal pyramids. In the third N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share corners with two NHf4 tetrahedra, corners with three OHf4 trigonal pyramids, corners with seven NHf4 trigonal pyramids, edges with two NHf4 trigonal pyramids, and edges with two OHf4 trigonal pyramids. In the fourth N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share corners with two NHf4 tetrahedra, corners with three OHf4 trigonal pyramids, corners with seven NHf4 trigonal pyramids, and edges with four OHf4 trigonal pyramids. In the fifth N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share a cornercorner with one NHf4 tetrahedra, corners with four OHf4 trigonal pyramids, corners with six NHf4 trigonal pyramids, edges with two NHf4 trigonal pyramids, and edges with two OHf4 trigonal pyramids. In the sixth N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 tetrahedra that share corners with five OHf4 trigonal pyramids, corners with six NHf4 trigonal pyramids, edges with two NHf4 trigonal pyramids, and edges with two OHf4 trigonal pyramids. In the seventh N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share a cornercorner with one NHf4 tetrahedra, corners with five OHf4 trigonal pyramids, corners with six NHf4 trigonal pyramids, an edgeedge with one OHf4 trigonal pyramid, and edges with three NHf4 trigonal pyramids. In the eighth N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share a cornercorner with one NHf4 tetrahedra, corners with four OHf4 trigonal pyramids, corners with seven NHf4 trigonal pyramids, edges with two NHf4 trigonal pyramids, and edges with two OHf4 trigonal pyramids. In the ninth N3- site, N3- is bonded to four Hf4+ atoms to form NHf4 trigonal pyramids that share a cornercorner with one NHf4 tetrahedra, corners with four OHf4 trigonal pyramids, corners with seven NHf4 trigonal pyramids, an edgeedge with one OHf4 trigonal pyramid, and edges with two NHf4 trigonal pyramids. In the tenth N3- site, N3- is bonded to four Hf4+ atoms to form NHf4 trigonal pyramids that share a cornercorner with one NHf4 tetrahedra, corners with five OHf4 trigonal pyramids, corners with six NHf4 trigonal pyramids, an edgeedge with one NHf4 tetrahedra, an edgeedge with one OHf4 trigonal pyramid, and edges with two NHf4 trigonal pyramids. In the eleventh N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share corners with two NHf4 tetrahedra, corners with four NHf4 trigonal pyramids, corners with six OHf4 trigonal pyramids, and edges with four NHf4 trigonal pyramids. In the twelfth N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share corners with five OHf4 trigonal pyramids, corners with six NHf4 trigonal pyramids, an edgeedge with one OHf4 trigonal pyramid, and edges with three NHf4 trigonal pyramids. In the thirteenth N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share a cornercorner with one NHf4 tetrahedra, corners with five OHf4 trigonal pyramids, corners with six NHf4 trigonal pyramids, an edgeedge with one NHf4 tetrahedra, and edges with two OHf4 trigonal pyramids. In the fourteenth N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share corners with two NHf4 tetrahedra, corners with three OHf4 trigonal pyramids, corners with seven NHf4 trigonal pyramids, an edgeedge with one OHf4 trigonal pyramid, and edges with two NHf4 trigonal pyramids. In the fifteenth N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share a cornercorner with one NHf4 tetrahedra, corners with three OHf4 trigonal pyramids, corners with seven NHf4 trigonal pyramids, an edgeedge with one OHf4 trigonal pyramid, and edges with three NHf4 trigonal pyramids. In the sixteenth N3- site, N3- is bonded in a distorted rectangular see-saw-like geometry to four Hf4+ atoms. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded to four Hf4+ atoms to form distorted OHf4 trigonal pyramids that share a cornercorner with one NHf4 tetrahedra, corners with four OHf4 trigonal pyramids, corners with seven NHf4 trigonal pyramids, an edgeedge with one NHf4 tetrahedra, an edgeedge with one NHf4 trigonal pyramid, and an edgeedge with one OHf4 trigonal pyramid. In the second O2- site, O2- is bonded to four Hf4+ atoms to form distorted OHf4 trigonal pyramids that share corners with two NHf4 tetrahedra, corners with four NHf4 trigonal pyramids, corners with six OHf4 trigonal pyramids, and edges with four NHf4 trigonal pyramids. In the third O2- site, O2- is bonded to four Hf4+ atoms to form distorted OHf4 trigonal pyramids that share a cornercorner with one NHf4 tetrahedra, corners with four OHf4 trigonal pyramids, corners with six NHf4 trigonal pyramids, an edgeedge with one NHf4 tetrahedra, and edges with three NHf4 trigonal pyramids. In the fourth O2- site, O2- is bonded to four Hf4+ atoms to form distorted OHf4 trigonal pyramids that share a cornercorner with one NHf4 tetrahedra, corners with three OHf4 trigonal pyramids, corners with seven NHf4 trigonal pyramids, edges with two NHf4 trigonal pyramids, and edges with two OHf4 trigonal pyramids. In the fifth O2- site, O2- is bonded to four Hf4+ atoms to form distorted OHf4 trigonal pyramids that share corners with two OHf4 trigon

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Hf2N2O by Materials Project

Hf2ON2 is Ilmenite-like structured and crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are sixteen inequivalent Hf4+ sites. In the first Hf4+ site, Hf4+ is bonded to four N3- and two O2- atoms to form a mixture of distorted corner and edge-sharing HfN4O2 octahedra. The corner-sharing octahedra tilt angles range from 52–56°. There are a spread of Hf–N bond distances ranging from 2.11–2.22 Å. There are one shorter (2.20 Å) and one longer (2.22 Å) Hf–O bond lengths. In the second Hf4+ site, Hf4+ is bonded to four N3- and two O2- atoms to form a mixture of corner and edge-sharing HfN4O2 octahedra. The corner-sharing octahedra tilt angles range from 52–58°. There are a spread of Hf–N bond distances ranging from 2.09–2.17 Å. There are one shorter (2.22 Å) and one longer (2.27 Å) Hf–O bond lengths. In the third Hf4+ site, Hf4+ is bonded to four N3- and two O2- atoms to form a mixture of distorted corner and edge-sharing HfN4O2 octahedra. The corner-sharing octahedra tilt angles range from 51–55°. There are a spread of Hf–N bond distances ranging from 2.12–2.25 Å. There are one shorter (2.11 Å) and one longer (2.24 Å) Hf–O bond lengths. In the fourth Hf4+ site, Hf4+ is bonded to four N3- and two O2- atoms to form a mixture of corner and edge-sharing HfN4O2 octahedra. The corner-sharing octahedra tilt angles range from 52–57°. There are a spread of Hf–N bond distances ranging from 2.09–2.17 Å. There are one shorter (2.26 Å) and one longer (2.27 Å) Hf–O bond lengths. In the fifth Hf4+ site, Hf4+ is bonded to five N3- and one O2- atom to form a mixture of corner and edge-sharing HfN5O octahedra. The corner-sharing octahedra tilt angles range from 54–59°. There are a spread of Hf–N bond distances ranging from 2.11–2.22 Å. The Hf–O bond length is 2.29 Å. In the sixth Hf4+ site, Hf4+ is bonded to four N3- and two O2- atoms to form distorted HfN4O2 octahedra that share corners with five HfN5O octahedra, a cornercorner with one HfN4O2 pentagonal pyramid, and edges with six HfN4O2 octahedra. The corner-sharing octahedra tilt angles range from 53–57°. There are a spread of Hf–N bond distances ranging from 2.08–2.21 Å. There are one shorter (2.22 Å) and one longer (2.29 Å) Hf–O bond lengths. In the seventh Hf4+ site, Hf4+ is bonded to three N3- and three O2- atoms to form a mixture of distorted corner and edge-sharing HfN3O3 octahedra. The corner-sharing octahedra tilt angles range from 48–57°. There are a spread of Hf–N bond distances ranging from 2.13–2.18 Å. There are a spread of Hf–O bond distances ranging from 2.11–2.18 Å. In the eighth Hf4+ site, Hf4+ is bonded to four N3- and two O2- atoms to form a mixture of distorted corner and edge-sharing HfN4O2 octahedra. The corner-sharing octahedra tilt angles range from 52–59°. There are a spread of Hf–N bond distances ranging from 2.13–2.22 Å. There are one shorter (2.13 Å) and one longer (2.21 Å) Hf–O bond lengths. In the ninth Hf4+ site, Hf4+ is bonded to four N3- and two O2- atoms to form a mixture of distorted corner and edge-sharing HfN4O2 octahedra. The corner-sharing octahedra tilt angles range from 52–55°. There are a spread of Hf–N bond distances ranging from 2.13–2.21 Å. There are one shorter (2.15 Å) and one longer (2.19 Å) Hf–O bond lengths. In the tenth Hf4+ site, Hf4+ is bonded to four N3- and two O2- atoms to form a mixture of distorted corner and edge-sharing HfN4O2 pentagonal pyramids. The corner-sharing octahedra tilt angles range from 50–55°. There are a spread of Hf–N bond distances ranging from 2.15–2.19 Å. There are one shorter (2.16 Å) and one longer (2.18 Å) Hf–O bond lengths. In the eleventh Hf4+ site, Hf4+ is bonded to four N3- and two O2- atoms to form a mixture of distorted corner and edge-sharing HfN4O2 octahedra. The corner-sharing octahedra tilt angles range from 51–56°. There are a spread of Hf–N bond distances ranging from 2.08–2.20 Å. There are one shorter (2.23 Å) and one longer (2.31 Å) Hf–O bond lengths. In the twelfth Hf4+ site, Hf4+ is bonded to five N3- and one O2- atom to form a mixture of distorted corner and edge-sharing HfN5O octahedra. The corner-sharing octahedra tilt angles range from 52–56°. There are a spread of Hf–N bond distances ranging from 2.10–2.22 Å. The Hf–O bond length is 2.29 Å. In the thirteenth Hf4+ site, Hf4+ is bonded to four N3- and two O2- atoms to form a mixture of distorted corner and edge-sharing HfN4O2 octahedra. The corner-sharing octahedra tilt angles range from 52–58°. There are a spread of Hf–N bond distances ranging from 2.11–2.29 Å. There are one shorter (2.13 Å) and one longer (2.24 Å) Hf–O bond lengths. In the fourteenth Hf4+ site, Hf4+ is bonded to three N3- and three O2- atoms to form a mixture of corner and edge-sharing HfN3O3 octahedra. The corner-sharing octahedra tilt angles range from 52–56°. There are a spread of Hf–N bond distances ranging from 2.08–2.18 Å. There are a spread of Hf–O bond distances ranging from 2.15–2.25 Å. In the fifteenth Hf4+ site, Hf4+ is bonded to four N3- and two O2- atoms to form distorted HfN4O2 octahedra that share corners with six HfN4O2 octahedra, edges with five HfN5O octahedra, and an edgeedge with one HfN4O2 pentagonal pyramid. The corner-sharing octahedra tilt angles range from 53–56°. There are a spread of Hf–N bond distances ranging from 2.09–2.15 Å. There are one shorter (2.29 Å) and one longer (2.32 Å) Hf–O bond lengths. In the sixteenth Hf4+ site, Hf4+ is bonded to four N3- and two O2- atoms to form a mixture of distorted corner and edge-sharing HfN4O2 octahedra. The corner-sharing octahedra tilt angles range from 48–58°. There are a spread of Hf–N bond distances ranging from 2.12–2.22 Å. There are one shorter (2.20 Å) and one longer (2.21 Å) Hf–O bond lengths. There are sixteen inequivalent N3- sites. In the first N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share corners with two NHf4 tetrahedra, corners with four NHf4 trigonal pyramids, corners with six OHf4 trigonal pyramids, an edgeedge with one NHf4 tetrahedra, an edgeedge with one NHf4 trigonal pyramid, and edges with two OHf4 trigonal pyramids. In the second N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share a cornercorner with one NHf4 tetrahedra, corners with two OHf4 trigonal pyramids, corners with nine NHf4 trigonal pyramids, an edgeedge with one NHf4 trigonal pyramid, and edges with three OHf4 trigonal pyramids. In the third N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share a cornercorner with one NHf4 tetrahedra, corners with four OHf4 trigonal pyramids, corners with seven NHf4 trigonal pyramids, edges with two NHf4 trigonal pyramids, and edges with two OHf4 trigonal pyramids. In the fourth N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share a cornercorner with one NHf4 tetrahedra, corners with five OHf4 trigonal pyramids, corners with six NHf4 trigonal pyramids, an edgeedge with one OHf4 trigonal pyramid, and edges with three NHf4 trigonal pyramids. In the fifth N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 tetrahedra that share a cornercorner with one NHf4 tetrahedra, corners with four OHf4 trigonal pyramids, corners with seven NHf4 trigonal pyramids, an edgeedge with one NHf4 tetrahedra, an edgeedge with one NHf4 trigonal pyramid, and edges with two OHf4 trigonal pyramids. In the sixth N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share corners with two NHf4 tetrahedra, corners with three OHf4 trigonal pyramids, corners with seven NHf4 trigonal pyramids, an edgeedge with one NHf4 tetrahedra, an edgeedge with one NHf4 trigonal pyramid, and edges with two OHf4 trigonal pyramids. In the seventh N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share corners with two NHf4 tetrahedra, corners with four OHf4 trigonal pyramids, corners with six NHf4 trigonal pyramids, an edgeedge with one OHf4 trigonal pyramid, and edges with three NHf4 trigonal pyramids. In the eighth N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share corners with two NHf4 tetrahedra, corners with four NHf4 trigonal pyramids, corners with six OHf4 trigonal pyramids, an edgeedge with one OHf4 trigonal pyramid, and edges with three NHf4 trigonal pyramids. In the ninth N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share corners with two NHf4 tetrahedra, corners with three OHf4 trigonal pyramids, corners with seven NHf4 trigonal pyramids, edges with two NHf4 trigonal pyramids, and edges with two OHf4 trigonal pyramids. In the tenth N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share corners with two NHf4 tetrahedra, corners with four OHf4 trigonal pyramids, corners with six NHf4 trigonal pyramids, an edgeedge with one NHf4 tetrahedra, an edgeedge with one NHf4 trigonal pyramid, and edges with two OHf4 trigonal pyramids. In the eleventh N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share corners with two NHf4 tetrahedra, corners with four OHf4 trigonal pyramids, corners with six NHf4 trigonal pyramids, edges with two NHf4 trigonal pyramids, and edges with two OHf4 trigonal pyramids. In the twelfth N3- site, N3- is bonded to four Hf4+ atoms to form NHf4 trigonal pyramids that share corners with two NHf4 tetrahedra, corners with four NHf4 trigonal pyramids, corners with six OHf4 trigonal pyramids, and edges with four NHf4 trigonal pyramids. In the thirteenth N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 tetrahedra that share a cornercorner with one NHf4 tetrahedra, corners with five OHf4 trigonal pyramids, corners with six NHf4 trigonal pyramids, edges with two NHf4 trigonal pyramids, and edges with two OHf4 trigonal pyramids. In the fourteenth N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 tetrahedra that share corners with five OHf4 trigonal pyramids, corners with seven NHf4 trigonal pyramids, an edgeedge with one NHf4 tetrahedra, an edgeedge with one NHf4 trigonal pyramid, and edges with two OHf4 trigonal pyramids. In the fifteenth N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share corners with five OHf4 trigonal pyramids, corners with seven NHf4 trigonal pyramids, an edgeedge with one OHf4 trigonal pyramid, and edges with three NHf4 trigonal pyramids. In the sixteenth N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share a cornercorner with one NHf4 tetrahedra, corners with two OHf4 trigonal pyramids, corners with nine NHf4 trigonal pyramids, an edgeedge with one NHf4 tetrahedra, and edges with three OHf4 trigonal pyramids. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded to four Hf4+ atoms to form distorted OHf4 trigonal pyramids that share corners with three NHf4 tetrahedra, corners with three OHf4 trigonal pyramids, corners with six NHf4 trigonal pyramids, an edgeedge with one OHf4 trigonal pyramid, and edges with three NHf4 trigonal pyramids. In the second O2- site, O2- is bonded to four Hf4+ atoms to form distorted OHf4 trigonal pyramids that share corners with three NHf4 tetrahedra, corners with three OHf4 trigonal pyramids, corners with six NHf4 trigonal pyramids, and edges with four NHf4 trigonal pyramids. In the third O2- site, O2- is bonded to four Hf4+ atoms to form distorted OHf4 trigonal pyramids that share corners with two NHf4 tetrahedra, corners with three OHf4 trigonal pyramids, corners with seven NHf4 trigonal pyramids, an edgeedge with one NHf4 tetrahedra, an edgeedge with one OHf4 trigonal pyramid, and edges with two NHf4 trigonal pyramids. In the fourth O2- site, O2- is bonded to four Hf4+ atoms to form distorted OH

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Li6VO5F by Materials Project

Li6VO5F crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are twelve inequivalent Li1+ sites. In the first Li1+ site, Li1+ is bonded to three O2- and one F1- atom to form distorted LiO3F trigonal pyramids that share corners with two VO4 tetrahedra, corners with three equivalent LiO3F tetrahedra, corners with five LiO3F trigonal pyramids, an edgeedge with one LiO4 tetrahedra, and edges with two LiO3F trigonal pyramids. There are a spread of Li–O bond distances ranging from 1.82–2.27 Å. The Li–F bond length is 1.98 Å. In the second Li1+ site, Li1+ is bonded to three O2- and one F1- atom to form LiO3F trigonal pyramids that share corners with three equivalent LiO4 tetrahedra, corners with three equivalent VO4 tetrahedra, corners with two LiO3F trigonal pyramids, an edgeedge with one LiO3F tetrahedra, and edges with two LiO3F trigonal pyramids. There are a spread of Li–O bond distances ranging from 1.94–2.03 Å. The Li–F bond length is 2.09 Å. In the third Li1+ site, Li1+ is bonded to four O2- atoms to form LiO4 tetrahedra that share corners with three equivalent VO4 tetrahedra, corners with five LiO3F trigonal pyramids, an edgeedge with one LiO3F tetrahedra, and edges with two LiO3F trigonal pyramids. There are a spread of Li–O bond distances ranging from 1.91–2.10 Å. In the fourth Li1+ site, Li1+ is bonded to three O2- and one F1- atom to form distorted LiO3F trigonal pyramids that share corners with two VO4 tetrahedra, corners with three equivalent LiO3F tetrahedra, corners with four LiO3F trigonal pyramids, an edgeedge with one LiO4 tetrahedra, and edges with two LiO3F trigonal pyramids. There is one shorter (1.88 Å) and two longer (2.00 Å) Li–O bond length. The Li–F bond length is 2.05 Å. In the fifth Li1+ site, Li1+ is bonded to three O2- and one F1- atom to form distorted LiO3F tetrahedra that share corners with two VO4 tetrahedra, corners with seven LiO3F trigonal pyramids, an edgeedge with one LiO4 tetrahedra, and edges with two LiO3F trigonal pyramids. There are a spread of Li–O bond distances ranging from 1.88–2.13 Å. The Li–F bond length is 1.92 Å. In the sixth Li1+ site, Li1+ is bonded to three O2- and one F1- atom to form distorted LiO3F trigonal pyramids that share corners with four LiO4 tetrahedra, corners with four LiO3F trigonal pyramids, an edgeedge with one LiO3F tetrahedra, an edgeedge with one VO4 tetrahedra, and edges with two LiO3F trigonal pyramids. There are a spread of Li–O bond distances ranging from 1.83–2.10 Å. The Li–F bond length is 1.97 Å. In the seventh Li1+ site, Li1+ is bonded to three O2- and one F1- atom to form distorted LiO3F trigonal pyramids that share corners with two VO4 tetrahedra, corners with three equivalent LiO3F tetrahedra, corners with four LiO3F trigonal pyramids, an edgeedge with one LiO4 tetrahedra, and edges with two LiO3F trigonal pyramids. There are a spread of Li–O bond distances ranging from 1.83–2.19 Å. The Li–F bond length is 2.00 Å. In the eighth Li1+ site, Li1+ is bonded to three O2- and one F1- atom to form distorted LiO3F tetrahedra that share corners with two VO4 tetrahedra, corners with eight LiO3F trigonal pyramids, an edgeedge with one LiO4 tetrahedra, and edges with two LiO3F trigonal pyramids. There are a spread of Li–O bond distances ranging from 1.87–2.19 Å. The Li–F bond length is 1.90 Å. In the ninth Li1+ site, Li1+ is bonded to four O2- atoms to form LiO4 tetrahedra that share corners with three equivalent VO4 tetrahedra, corners with five LiO3F trigonal pyramids, an edgeedge with one LiO3F tetrahedra, and edges with two LiO3F trigonal pyramids. There are a spread of Li–O bond distances ranging from 1.91–2.06 Å. In the tenth Li1+ site, Li1+ is bonded to three O2- and one F1- atom to form LiO3F trigonal pyramids that share corners with three equivalent LiO4 tetrahedra, corners with three equivalent VO4 tetrahedra, corners with two LiO3F trigonal pyramids, an edgeedge with one LiO3F tetrahedra, and edges with two LiO3F trigonal pyramids. There are a spread of Li–O bond distances ranging from 1.95–1.99 Å. The Li–F bond length is 2.09 Å. In the eleventh Li1+ site, Li1+ is bonded to three O2- and one F1- atom to form distorted LiO3F trigonal pyramids that share corners with three LiO4 tetrahedra, corners with five LiO3F trigonal pyramids, an edgeedge with one LiO3F tetrahedra, an edgeedge with one VO4 tetrahedra, and edges with two LiO3F trigonal pyramids. There are a spread of Li–O bond distances ranging from 1.84–2.09 Å. The Li–F bond length is 1.95 Å. In the twelfth Li1+ site, Li1+ is bonded to three O2- and one F1- atom to form distorted LiO3F trigonal pyramids that share corners with two VO4 tetrahedra, corners with three equivalent LiO3F tetrahedra, corners with four LiO3F trigonal pyramids, an edgeedge with one LiO4 tetrahedra, and edges with two LiO3F trigonal pyramids. There are a spread of Li–O bond distances ranging from 1.87–2.01 Å. The Li–F bond length is 2.05 Å. There are two inequivalent V5+ sites. In the first V5+ site, V5+ is bonded to four O2- atoms to form VO4 tetrahedra that share corners with five LiO4 tetrahedra, corners with seven LiO3F trigonal pyramids, and an edgeedge with one LiO3F trigonal pyramid. There is two shorter (1.73 Å) and two longer (1.77 Å) V–O bond length. In the second V5+ site, V5+ is bonded to four O2- atoms to form VO4 tetrahedra that share corners with five LiO3F tetrahedra, corners with seven LiO3F trigonal pyramids, and an edgeedge with one LiO3F trigonal pyramid. There is two shorter (1.73 Å) and two longer (1.77 Å) V–O bond length. There are ten inequivalent O2- sites. In the first O2- site, O2- is bonded to four Li1+ and one V5+ atom to form distorted OLi4V trigonal bipyramids that share corners with two equivalent FLi5 trigonal bipyramids, corners with three OLi5 trigonal bipyramids, corners with two OLi3V trigonal pyramids, an edgeedge with one FLi5 trigonal bipyramid, and edges with two OLi4V trigonal bipyramids. In the second O2- site, O2- is bonded in a 4-coordinate geometry to three Li1+ and one V5+ atom. In the third O2- site, O2- is bonded to three Li1+ and one V5+ atom to form distorted OLi3V trigonal pyramids that share corners with five OLi4V trigonal bipyramids, an edgeedge with one OLi5 trigonal bipyramid, and an edgeedge with one FLi5 trigonal bipyramid. In the fourth O2- site, O2- is bonded to five Li1+ atoms to form distorted OLi5 trigonal bipyramids that share corners with two equivalent FLi5 trigonal bipyramids, corners with three OLi4V trigonal bipyramids, an edgeedge with one FLi5 trigonal bipyramid, edges with two OLi4V trigonal bipyramids, and an edgeedge with one OLi3V trigonal pyramid. In the fifth O2- site, O2- is bonded to three Li1+ and one V5+ atom to form distorted OLi3V trigonal pyramids that share corners with five OLi4V trigonal bipyramids, an edgeedge with one OLi5 trigonal bipyramid, and an edgeedge with one FLi5 trigonal bipyramid. In the sixth O2- site, O2- is bonded to four Li1+ and one V5+ atom to form OLi4V trigonal bipyramids that share a cornercorner with one FLi5 trigonal bipyramid, corners with two OLi5 trigonal bipyramids, corners with three equivalent OLi3V trigonal pyramids, an edgeedge with one FLi5 trigonal bipyramid, and edges with two OLi5 trigonal bipyramids. In the seventh O2- site, O2- is bonded to five Li1+ atoms to form distorted OLi5 trigonal bipyramids that share corners with two equivalent FLi5 trigonal bipyramids, corners with three OLi4V trigonal bipyramids, an edgeedge with one FLi5 trigonal bipyramid, edges with two OLi4V trigonal bipyramids, and an edgeedge with one OLi3V trigonal pyramid. In the eighth O2- site, O2- is bonded to four Li1+ and one V5+ atom to form distorted OLi4V trigonal bipyramids that share a cornercorner with one FLi5 trigonal bipyramid, corners with two OLi4V trigonal bipyramids, corners with three equivalent OLi3V trigonal pyramids, an edgeedge with one FLi5 trigonal bipyramid, and edges with two OLi5 trigonal bipyramids. In the ninth O2- site, O2- is bonded in a 4-coordinate geometry to three Li1+ and one V5+ atom. In the tenth O2- site, O2- is bonded to four Li1+ and one V5+ atom to form distorted OLi4V trigonal bipyramids that share corners with two equivalent FLi5 trigonal bipyramids, corners with three OLi4V trigonal bipyramids, corners with two OLi3V trigonal pyramids, an edgeedge with one FLi5 trigonal bipyramid, and edges with two OLi5 trigonal bipyramids. There are two inequivalent F1- sites. In the first F1- site, F1- is bonded to five Li1+ atoms to form distorted FLi5 trigonal bipyramids that share corners with five OLi5 trigonal bipyramids, edges with three OLi4V trigonal bipyramids, and an edgeedge with one OLi3V trigonal pyramid. In the second F1- site, F1- is bonded to five Li1+ atoms to form distorted FLi5 trigonal bipyramids that share corners with five OLi5 trigonal bipyramids, edges with three OLi4V trigonal bipyramids, and an edgeedge with one OLi3V trigonal pyramid.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Zr2N2O by Materials Project

Zr2ON2 is Ilmenite-like structured and crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are sixteen inequivalent Zr4+ sites. In the first Zr4+ site, Zr4+ is bonded to four N3- and two O2- atoms to form a mixture of distorted edge and corner-sharing ZrN4O2 octahedra. The corner-sharing octahedra tilt angles range from 52–53°. There are a spread of Zr–N bond distances ranging from 2.16–2.25 Å. There are one shorter (2.18 Å) and one longer (2.24 Å) Zr–O bond lengths. In the second Zr4+ site, Zr4+ is bonded to four N3- and two O2- atoms to form a mixture of edge and corner-sharing ZrN4O2 octahedra. The corner-sharing octahedra tilt angles range from 54–59°. There are a spread of Zr–N bond distances ranging from 2.13–2.22 Å. There are one shorter (2.25 Å) and one longer (2.31 Å) Zr–O bond lengths. In the third Zr4+ site, Zr4+ is bonded to four N3- and two O2- atoms to form a mixture of distorted edge and corner-sharing ZrN4O2 octahedra. The corner-sharing octahedra tilt angles range from 52–57°. There are a spread of Zr–N bond distances ranging from 2.17–2.25 Å. There are one shorter (2.16 Å) and one longer (2.23 Å) Zr–O bond lengths. In the fourth Zr4+ site, Zr4+ is bonded to three N3- and three O2- atoms to form a mixture of distorted edge and corner-sharing ZrN3O3 octahedra. The corner-sharing octahedra tilt angles range from 51–55°. There are a spread of Zr–N bond distances ranging from 2.12–2.24 Å. There are a spread of Zr–O bond distances ranging from 2.17–2.24 Å. In the fifth Zr4+ site, Zr4+ is bonded to four N3- and two O2- atoms to form a mixture of distorted edge and corner-sharing ZrN4O2 octahedra. The corner-sharing octahedra tilt angles range from 52–56°. There are a spread of Zr–N bond distances ranging from 2.12–2.20 Å. There are one shorter (2.35 Å) and one longer (2.36 Å) Zr–O bond lengths. In the sixth Zr4+ site, Zr4+ is bonded to four N3- and two O2- atoms to form a mixture of distorted edge and corner-sharing ZrN4O2 octahedra. The corner-sharing octahedra tilt angles range from 52–55°. There are a spread of Zr–N bond distances ranging from 2.13–2.21 Å. There are one shorter (2.30 Å) and one longer (2.31 Å) Zr–O bond lengths. In the seventh Zr4+ site, Zr4+ is bonded to four N3- and two O2- atoms to form ZrN4O2 octahedra that share corners with six ZrN3O3 octahedra and edges with six ZrN4O2 octahedra. The corner-sharing octahedra tilt angles range from 52–58°. There are a spread of Zr–N bond distances ranging from 2.13–2.25 Å. There are one shorter (2.28 Å) and one longer (2.29 Å) Zr–O bond lengths. In the eighth Zr4+ site, Zr4+ is bonded to four N3- and two O2- atoms to form a mixture of edge and corner-sharing ZrN4O2 octahedra. The corner-sharing octahedra tilt angles range from 52–57°. There are a spread of Zr–N bond distances ranging from 2.18–2.22 Å. There are one shorter (2.17 Å) and one longer (2.23 Å) Zr–O bond lengths. In the ninth Zr4+ site, Zr4+ is bonded to four N3- and two O2- atoms to form ZrN4O2 octahedra that share corners with six ZrN4O2 octahedra and edges with six ZrN3O3 octahedra. The corner-sharing octahedra tilt angles range from 53–55°. There are a spread of Zr–N bond distances ranging from 2.11–2.22 Å. There are one shorter (2.31 Å) and one longer (2.32 Å) Zr–O bond lengths. In the tenth Zr4+ site, Zr4+ is bonded to five N3- and one O2- atom to form a mixture of distorted edge and corner-sharing ZrN5O octahedra. The corner-sharing octahedra tilt angles range from 52–56°. There are a spread of Zr–N bond distances ranging from 2.18–2.32 Å. The Zr–O bond length is 2.23 Å. In the eleventh Zr4+ site, Zr4+ is bonded to four N3- and two O2- atoms to form a mixture of distorted edge and corner-sharing ZrN4O2 octahedra. The corner-sharing octahedra tilt angles range from 51–55°. There are a spread of Zr–N bond distances ranging from 2.13–2.26 Å. There are one shorter (2.22 Å) and one longer (2.26 Å) Zr–O bond lengths. In the twelfth Zr4+ site, Zr4+ is bonded to five N3- and one O2- atom to form a mixture of distorted edge and corner-sharing ZrN5O octahedra. The corner-sharing octahedra tilt angles range from 51–59°. There are a spread of Zr–N bond distances ranging from 2.15–2.30 Å. The Zr–O bond length is 2.27 Å. In the thirteenth Zr4+ site, Zr4+ is bonded to three N3- and three O2- atoms to form a mixture of distorted edge and corner-sharing ZrN3O3 octahedra. The corner-sharing octahedra tilt angles range from 51–58°. There are a spread of Zr–N bond distances ranging from 2.12–2.28 Å. There are a spread of Zr–O bond distances ranging from 2.17–2.26 Å. In the fourteenth Zr4+ site, Zr4+ is bonded to four N3- and two O2- atoms to form a mixture of distorted edge and corner-sharing ZrN4O2 octahedra. The corner-sharing octahedra tilt angles range from 51–58°. There are a spread of Zr–N bond distances ranging from 2.14–2.26 Å. There are one shorter (2.26 Å) and one longer (2.28 Å) Zr–O bond lengths. In the fifteenth Zr4+ site, Zr4+ is bonded to five N3- and one O2- atom to form a mixture of distorted edge and corner-sharing ZrN5O octahedra. The corner-sharing octahedra tilt angles range from 51–57°. There are a spread of Zr–N bond distances ranging from 2.17–2.25 Å. The Zr–O bond length is 2.25 Å. In the sixteenth Zr4+ site, Zr4+ is bonded to three N3- and three O2- atoms to form a mixture of distorted edge and corner-sharing ZrN3O3 octahedra. The corner-sharing octahedra tilt angles range from 51–55°. There are a spread of Zr–N bond distances ranging from 2.16–2.19 Å. There are a spread of Zr–O bond distances ranging from 2.15–2.24 Å. There are sixteen inequivalent N3- sites. In the first N3- site, N3- is bonded to four Zr4+ atoms to form distorted NZr4 trigonal pyramids that share a cornercorner with one OZr4 tetrahedra, corners with four OZr4 trigonal pyramids, corners with seven NZr4 trigonal pyramids, edges with two NZr4 trigonal pyramids, and edges with two OZr4 trigonal pyramids. In the second N3- site, N3- is bonded to four Zr4+ atoms to form distorted NZr4 trigonal pyramids that share a cornercorner with one OZr4 tetrahedra, corners with three OZr4 trigonal pyramids, corners with eight NZr4 trigonal pyramids, an edgeedge with one NZr4 tetrahedra, an edgeedge with one NZr4 trigonal pyramid, and edges with two OZr4 trigonal pyramids. In the third N3- site, N3- is bonded to four Zr4+ atoms to form distorted NZr4 trigonal pyramids that share a cornercorner with one NZr4 tetrahedra, a cornercorner with one OZr4 tetrahedra, corners with two OZr4 trigonal pyramids, corners with seven NZr4 trigonal pyramids, edges with two NZr4 trigonal pyramids, and edges with two OZr4 trigonal pyramids. In the fourth N3- site, N3- is bonded to four Zr4+ atoms to form distorted NZr4 trigonal pyramids that share a cornercorner with one NZr4 tetrahedra, corners with three OZr4 trigonal pyramids, corners with seven NZr4 trigonal pyramids, an edgeedge with one OZr4 tetrahedra, an edgeedge with one NZr4 trigonal pyramid, and edges with two OZr4 trigonal pyramids. In the fifth N3- site, N3- is bonded to four Zr4+ atoms to form distorted NZr4 trigonal pyramids that share a cornercorner with one NZr4 tetrahedra, a cornercorner with one OZr4 tetrahedra, corners with two OZr4 trigonal pyramids, corners with seven NZr4 trigonal pyramids, an edgeedge with one NZr4 trigonal pyramid, and edges with three OZr4 trigonal pyramids. In the sixth N3- site, N3- is bonded to four Zr4+ atoms to form distorted NZr4 trigonal pyramids that share a cornercorner with one OZr4 tetrahedra, corners with three OZr4 trigonal pyramids, corners with eight NZr4 trigonal pyramids, an edgeedge with one NZr4 tetrahedra, an edgeedge with one OZr4 trigonal pyramid, and edges with two NZr4 trigonal pyramids. In the seventh N3- site, N3- is bonded to four Zr4+ atoms to form distorted NZr4 trigonal pyramids that share a cornercorner with one OZr4 tetrahedra, corners with four OZr4 trigonal pyramids, corners with seven NZr4 trigonal pyramids, an edgeedge with one NZr4 tetrahedra, an edgeedge with one NZr4 trigonal pyramid, and an edgeedge with one OZr4 trigonal pyramid. In the eighth N3- site, N3- is bonded to four Zr4+ atoms to form distorted NZr4 trigonal pyramids that share corners with five OZr4 trigonal pyramids, corners with seven NZr4 trigonal pyramids, an edgeedge with one OZr4 tetrahedra, an edgeedge with one OZr4 trigonal pyramid, and edges with two NZr4 trigonal pyramids. In the ninth N3- site, N3- is bonded to four Zr4+ atoms to form distorted NZr4 trigonal pyramids that share a cornercorner with one NZr4 tetrahedra, a cornercorner with one OZr4 tetrahedra, corners with three OZr4 trigonal pyramids, corners with six NZr4 trigonal pyramids, an edgeedge with one OZr4 trigonal pyramid, and edges with three NZr4 trigonal pyramids. In the tenth N3- site, N3- is bonded in a distorted rectangular see-saw-like geometry to four Zr4+ atoms. In the eleventh N3- site, N3- is bonded to four Zr4+ atoms to form distorted NZr4 tetrahedra that share corners with five OZr4 trigonal pyramids, corners with seven NZr4 trigonal pyramids, an edgeedge with one OZr4 tetrahedra, and edges with three NZr4 trigonal pyramids. In the twelfth N3- site, N3- is bonded to four Zr4+ atoms to form distorted NZr4 trigonal pyramids that share a cornercorner with one OZr4 tetrahedra, corners with four OZr4 trigonal pyramids, corners with seven NZr4 trigonal pyramids, an edgeedge with one OZr4 trigonal pyramid, and edges with three NZr4 trigonal pyramids. In the thirteenth N3- site, N3- is bonded to four Zr4+ atoms to form distorted NZr4 trigonal pyramids that share corners with four OZr4 trigonal pyramids, corners with eight NZr4 trigonal pyramids, an edgeedge with one NZr4 trigonal pyramid, and edges with two OZr4 trigonal pyramids. In the fourteenth N3- site, N3- is bonded to four Zr4+ atoms to form distorted NZr4 trigonal pyramids that share a cornercorner with one NZr4 tetrahedra, corners with four OZr4 trigonal pyramids, corners with six NZr4 trigonal pyramids, edges with two NZr4 trigonal pyramids, and edges with two OZr4 trigonal pyramids. In the fifteenth N3- site, N3- is bonded to four Zr4+ atoms to form distorted NZr4 trigonal pyramids that share a cornercorner with one NZr4 tetrahedra, corners with four OZr4 trigonal pyramids, corners with six NZr4 trigonal pyramids, an edgeedge with one OZr4 trigonal pyramid, and edges with three NZr4 trigonal pyramids. In the sixteenth N3- site, N3- is bonded to four Zr4+ atoms to form distorted NZr4 trigonal pyramids that share a cornercorner with one NZr4 tetrahedra, corners with three OZr4 trigonal pyramids, corners with seven NZr4 trigonal pyramids, edges with two NZr4 trigonal pyramids, and edges with two OZr4 trigonal pyramids. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded to four Zr4+ atoms to form distorted OZr4 trigonal pyramids that share a cornercorner with one OZr4 tetrahedra, corners with three OZr4 trigonal pyramids, corners with eight NZr4 trigonal pyramids, an edgeedge with one OZr4 trigonal pyramid, and edges with two NZr4 trigonal pyramids. In the second O2- site, O2- is bonded to four Zr4+ atoms to form distorted OZr4 trigonal pyramids that share a cornercorner with one NZr4 tetrahedra, a cornercorner with one OZr4 tetrahedra, corners with three OZr4 trigonal pyramids, corners with six NZr4 trigonal pyramids, and edges with four NZr4 trigonal pyramids. In the third O2- site, O2- is bonded to four Zr4+ atoms to form distorted OZr4 tetrahedra that share corners with four OZr4 trigonal pyramids, corners with eight NZr4 trigonal pyramids, an edgeedge with one NZr4 tetrahedra, an edgeedge with one OZr4 trigonal pyramid, and edges with two NZr4 trigonal pyramids. In the fourth O2- site, O2- is bonded to four Zr4+ atoms to form distorted OZr4 trigonal pyramids that share a cornercorner with one NZr4 tetrahedra, corners with three OZr4 trigonal pyramids, corners with

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Zr2N2O by Materials Project

Zr2ON2 is Ilmenite-like structured and crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are sixteen inequivalent Zr4+ sites. In the first Zr4+ site, Zr4+ is bonded to three N3- and three O2- atoms to form a mixture of edge and corner-sharing ZrN3O3 octahedra. The corner-sharing octahedra tilt angles range from 51–58°. There are a spread of Zr–N bond distances ranging from 2.12–2.15 Å. There are a spread of Zr–O bond distances ranging from 2.23–2.28 Å. In the second Zr4+ site, Zr4+ is bonded to three N3- and three O2- atoms to form a mixture of distorted edge and corner-sharing ZrN3O3 octahedra. The corner-sharing octahedra tilt angles range from 51–53°. There are one shorter (2.15 Å) and two longer (2.19 Å) Zr–N bond lengths. There are a spread of Zr–O bond distances ranging from 2.15–2.27 Å. In the third Zr4+ site, Zr4+ is bonded to four N3- and two O2- atoms to form distorted ZrN4O2 octahedra that share corners with five ZrN3O3 octahedra, a cornercorner with one ZrN3O3 pentagonal pyramid, and edges with six ZrN5O octahedra. The corner-sharing octahedra tilt angles range from 51–55°. There are a spread of Zr–N bond distances ranging from 2.17–2.26 Å. There are one shorter (2.18 Å) and one longer (2.24 Å) Zr–O bond lengths. In the fourth Zr4+ site, Zr4+ is bonded to three N3- and three O2- atoms to form distorted ZrN3O3 octahedra that share corners with six ZrN5O octahedra, edges with five ZrN3O3 octahedra, and an edgeedge with one ZrN3O3 pentagonal pyramid. The corner-sharing octahedra tilt angles range from 52–58°. There are a spread of Zr–N bond distances ranging from 2.11–2.14 Å. There are one shorter (2.22 Å) and two longer (2.34 Å) Zr–O bond lengths. In the fifth Zr4+ site, Zr4+ is bonded to three N3- and three O2- atoms to form distorted ZrN3O3 pentagonal pyramids that share corners with six ZrN4O2 octahedra and edges with six ZrN3O3 octahedra. The corner-sharing octahedra tilt angles range from 48–57°. There are a spread of Zr–N bond distances ranging from 2.09–2.22 Å. There are a spread of Zr–O bond distances ranging from 2.17–2.27 Å. In the sixth Zr4+ site, Zr4+ is bonded to five N3- and one O2- atom to form a mixture of edge and corner-sharing ZrN5O octahedra. The corner-sharing octahedra tilt angles range from 53–60°. There are a spread of Zr–N bond distances ranging from 2.13–2.25 Å. The Zr–O bond length is 2.35 Å. In the seventh Zr4+ site, Zr4+ is bonded to four N3- and two O2- atoms to form ZrN4O2 octahedra that share corners with six ZrN3O3 octahedra, edges with five ZrN4O2 octahedra, and an edgeedge with one ZrN3O3 pentagonal pyramid. The corner-sharing octahedra tilt angles range from 53–56°. There are a spread of Zr–N bond distances ranging from 2.18–2.23 Å. There are one shorter (2.18 Å) and one longer (2.22 Å) Zr–O bond lengths. In the eighth Zr4+ site, Zr4+ is bonded to four N3- and two O2- atoms to form ZrN4O2 octahedra that share corners with five ZrN4O2 octahedra, a cornercorner with one ZrN3O3 pentagonal pyramid, and edges with six ZrN3O3 octahedra. The corner-sharing octahedra tilt angles range from 53–59°. There are a spread of Zr–N bond distances ranging from 2.11–2.22 Å. Both Zr–O bond lengths are 2.32 Å. In the ninth Zr4+ site, Zr4+ is bonded to three N3- and three O2- atoms to form a mixture of distorted edge and corner-sharing ZrN3O3 octahedra. The corner-sharing octahedra tilt angles range from 51–55°. There are two shorter (2.14 Å) and one longer (2.25 Å) Zr–N bond lengths. There are a spread of Zr–O bond distances ranging from 2.16–2.24 Å. In the tenth Zr4+ site, Zr4+ is bonded to four N3- and two O2- atoms to form a mixture of distorted edge and corner-sharing ZrN4O2 octahedra. The corner-sharing octahedra tilt angles range from 52–55°. There are two shorter (2.18 Å) and two longer (2.22 Å) Zr–N bond lengths. There are one shorter (2.19 Å) and one longer (2.20 Å) Zr–O bond lengths. In the eleventh Zr4+ site, Zr4+ is bonded to five N3- and one O2- atom to form a mixture of distorted edge and corner-sharing ZrN5O octahedra. The corner-sharing octahedra tilt angles range from 52–60°. There are a spread of Zr–N bond distances ranging from 2.15–2.28 Å. The Zr–O bond length is 2.28 Å. In the twelfth Zr4+ site, Zr4+ is bonded to four N3- and two O2- atoms to form a mixture of distorted edge and corner-sharing ZrN4O2 octahedra. The corner-sharing octahedra tilt angles range from 52–59°. There are a spread of Zr–N bond distances ranging from 2.17–2.24 Å. There are one shorter (2.20 Å) and one longer (2.25 Å) Zr–O bond lengths. In the thirteenth Zr4+ site, Zr4+ is bonded to five N3- and one O2- atom to form a mixture of distorted edge and corner-sharing ZrN5O octahedra. The corner-sharing octahedra tilt angles range from 52–56°. There are a spread of Zr–N bond distances ranging from 2.15–2.23 Å. The Zr–O bond length is 2.32 Å. In the fourteenth Zr4+ site, Zr4+ is bonded to four N3- and two O2- atoms to form a mixture of distorted edge and corner-sharing ZrN4O2 octahedra. The corner-sharing octahedra tilt angles range from 52–57°. There are a spread of Zr–N bond distances ranging from 2.12–2.20 Å. There are one shorter (2.33 Å) and one longer (2.37 Å) Zr–O bond lengths. In the fifteenth Zr4+ site, Zr4+ is bonded to five N3- and one O2- atom to form a mixture of distorted edge and corner-sharing ZrN5O octahedra. The corner-sharing octahedra tilt angles range from 51–56°. There are a spread of Zr–N bond distances ranging from 2.17–2.28 Å. The Zr–O bond length is 2.24 Å. In the sixteenth Zr4+ site, Zr4+ is bonded to five N3- and one O2- atom to form distorted ZrN5O octahedra that share corners with six ZrN3O3 octahedra and edges with six ZrN4O2 octahedra. The corner-sharing octahedra tilt angles range from 52–55°. There are a spread of Zr–N bond distances ranging from 2.19–2.27 Å. The Zr–O bond length is 2.23 Å. There are sixteen inequivalent N3- sites. In the first N3- site, N3- is bonded to four Zr4+ atoms to form distorted NZr4 trigonal pyramids that share corners with four NZr4 tetrahedra, corners with two OZr4 trigonal pyramids, corners with six NZr4 trigonal pyramids, an edgeedge with one NZr4 trigonal pyramid, and edges with three OZr4 trigonal pyramids. In the second N3- site, N3- is bonded to four Zr4+ atoms to form distorted NZr4 tetrahedra that share corners with two NZr4 tetrahedra, corners with four OZr4 trigonal pyramids, corners with six NZr4 trigonal pyramids, an edgeedge with one NZr4 trigonal pyramid, and edges with three OZr4 trigonal pyramids. In the third N3- site, N3- is bonded to four Zr4+ atoms to form distorted NZr4 tetrahedra that share corners with three NZr4 tetrahedra, corners with three OZr4 trigonal pyramids, corners with six NZr4 trigonal pyramids, an edgeedge with one NZr4 trigonal pyramid, and edges with three OZr4 trigonal pyramids. In the fourth N3- site, N3- is bonded to four Zr4+ atoms to form distorted NZr4 trigonal pyramids that share corners with three NZr4 tetrahedra, corners with three OZr4 trigonal pyramids, corners with six NZr4 trigonal pyramids, edges with two NZr4 trigonal pyramids, and edges with two OZr4 trigonal pyramids. In the fifth N3- site, N3- is bonded to four Zr4+ atoms to form distorted NZr4 trigonal pyramids that share corners with two NZr4 tetrahedra, corners with four OZr4 trigonal pyramids, corners with six NZr4 trigonal pyramids, edges with two NZr4 trigonal pyramids, and edges with two OZr4 trigonal pyramids. In the sixth N3- site, N3- is bonded to four Zr4+ atoms to form distorted NZr4 trigonal pyramids that share a cornercorner with one NZr4 tetrahedra, corners with five OZr4 trigonal pyramids, corners with six NZr4 trigonal pyramids, an edgeedge with one NZr4 tetrahedra, an edgeedge with one OZr4 trigonal pyramid, and edges with two NZr4 trigonal pyramids. In the seventh N3- site, N3- is bonded to four Zr4+ atoms to form distorted NZr4 tetrahedra that share corners with two NZr4 tetrahedra, corners with four OZr4 trigonal pyramids, corners with six NZr4 trigonal pyramids, edges with two NZr4 trigonal pyramids, and edges with two OZr4 trigonal pyramids. In the eighth N3- site, N3- is bonded to four Zr4+ atoms to form distorted NZr4 trigonal pyramids that share corners with six NZr4 trigonal pyramids, corners with six OZr4 trigonal pyramids, edges with two NZr4 tetrahedra, and edges with two NZr4 trigonal pyramids. In the ninth N3- site, N3- is bonded to four Zr4+ atoms to form distorted NZr4 trigonal pyramids that share corners with two NZr4 tetrahedra, corners with four OZr4 trigonal pyramids, corners with six NZr4 trigonal pyramids, an edgeedge with one OZr4 trigonal pyramid, and edges with three NZr4 trigonal pyramids. In the tenth N3- site, N3- is bonded to four Zr4+ atoms to form distorted NZr4 trigonal pyramids that share corners with three NZr4 tetrahedra, corners with three OZr4 trigonal pyramids, corners with six NZr4 trigonal pyramids, an edgeedge with one NZr4 trigonal pyramid, and edges with three OZr4 trigonal pyramids. In the eleventh N3- site, N3- is bonded to four Zr4+ atoms to form distorted NZr4 trigonal pyramids that share a cornercorner with one NZr4 tetrahedra, corners with five OZr4 trigonal pyramids, corners with six NZr4 trigonal pyramids, an edgeedge with one NZr4 tetrahedra, an edgeedge with one OZr4 trigonal pyramid, and edges with two NZr4 trigonal pyramids. In the twelfth N3- site, N3- is bonded to four Zr4+ atoms to form distorted NZr4 tetrahedra that share corners with three NZr4 tetrahedra, corners with three OZr4 trigonal pyramids, corners with six NZr4 trigonal pyramids, edges with two NZr4 trigonal pyramids, and edges with two OZr4 trigonal pyramids. In the thirteenth N3- site, N3- is bonded to four Zr4+ atoms to form distorted NZr4 trigonal pyramids that share corners with three NZr4 tetrahedra, corners with three OZr4 trigonal pyramids, corners with six NZr4 trigonal pyramids, an edgeedge with one OZr4 trigonal pyramid, and edges with three NZr4 trigonal pyramids. In the fourteenth N3- site, N3- is bonded to four Zr4+ atoms to form distorted NZr4 trigonal pyramids that share a cornercorner with one NZr4 tetrahedra, corners with five OZr4 trigonal pyramids, corners with six NZr4 trigonal pyramids, edges with two NZr4 tetrahedra, an edgeedge with one NZr4 trigonal pyramid, and an edgeedge with one OZr4 trigonal pyramid. In the fifteenth N3- site, N3- is bonded to four Zr4+ atoms to form distorted NZr4 trigonal pyramids that share a cornercorner with one NZr4 tetrahedra, corners with five OZr4 trigonal pyramids, corners with six NZr4 trigonal pyramids, an edgeedge with one OZr4 trigonal pyramid, and edges with three NZr4 trigonal pyramids. In the sixteenth N3- site, N3- is bonded to four Zr4+ atoms to form distorted NZr4 trigonal pyramids that share corners with three NZr4 tetrahedra, corners with three OZr4 trigonal pyramids, corners with six NZr4 trigonal pyramids, edges with two NZr4 trigonal pyramids, and edges with two OZr4 trigonal pyramids. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded to four Zr4+ atoms to form distorted OZr4 trigonal pyramids that share corners with six NZr4 trigonal pyramids, corners with six OZr4 trigonal pyramids, edges with two NZr4 tetrahedra, and edges with two NZr4 trigonal pyramids. In the second O2- site, O2- is bonded to four Zr4+ atoms to form distorted OZr4 trigonal pyramids that share corners with six NZr4 trigonal pyramids, corners with six OZr4 trigonal pyramids, an edgeedge with one NZr4 tetrahedra, and edges with three NZr4 trigonal pyramids. In the third O2- site, O2- is bonded to four Zr4+ atoms to form distorted OZr4 trigonal pyramids that share a cornercorner with one NZr4 tetrahedra, corners with five OZr4 trigonal pyramids, corners with six NZr4 trigonal pyramids, edges with two NZr4 tetrahedra, an edgeedge with one NZr4 trigonal pyramid, and an edgeedge with one OZr4 trigonal pyramid. In the fourth O2- sit

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Hf2N2O by Materials Project

Hf2ON2 is Ilmenite-like structured and crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are sixteen inequivalent Hf4+ sites. In the first Hf4+ site, Hf4+ is bonded to three N3- and three O2- atoms to form HfN3O3 octahedra that share corners with six HfN3O3 octahedra and edges with six HfN4O2 octahedra. The corner-sharing octahedra tilt angles range from 51–57°. There are a spread of Hf–N bond distances ranging from 2.09–2.13 Å. There are a spread of Hf–O bond distances ranging from 2.19–2.25 Å. In the second Hf4+ site, Hf4+ is bonded to three N3- and three O2- atoms to form distorted HfN3O3 octahedra that share corners with six HfN3O3 octahedra and edges with six HfN4O2 octahedra. The corner-sharing octahedra tilt angles range from 50–55°. There are a spread of Hf–N bond distances ranging from 2.08–2.21 Å. There are one shorter (2.13 Å) and two longer (2.19 Å) Hf–O bond lengths. In the third Hf4+ site, Hf4+ is bonded to four N3- and two O2- atoms to form distorted HfN4O2 octahedra that share corners with six HfN5O octahedra and edges with six HfN3O3 octahedra. The corner-sharing octahedra tilt angles range from 54–58°. There are a spread of Hf–N bond distances ranging from 2.08–2.18 Å. There are one shorter (2.29 Å) and one longer (2.33 Å) Hf–O bond lengths. In the fourth Hf4+ site, Hf4+ is bonded to three N3- and three O2- atoms to form distorted HfN3O3 octahedra that share corners with six HfN3O3 octahedra and edges with six HfN5O octahedra. The corner-sharing octahedra tilt angles range from 50–53°. There are a spread of Hf–N bond distances ranging from 2.11–2.17 Å. There are two shorter (2.15 Å) and one longer (2.20 Å) Hf–O bond lengths. In the fifth Hf4+ site, Hf4+ is bonded to three N3- and three O2- atoms to form a mixture of distorted corner and edge-sharing HfN3O3 octahedra. The corner-sharing octahedra tilt angles range from 50–56°. There are a spread of Hf–N bond distances ranging from 2.08–2.19 Å. There are a spread of Hf–O bond distances ranging from 2.13–2.20 Å. In the sixth Hf4+ site, Hf4+ is bonded to three N3- and three O2- atoms to form a mixture of distorted corner and edge-sharing HfN3O3 octahedra. The corner-sharing octahedra tilt angles range from 50–55°. There are a spread of Hf–N bond distances ranging from 2.10–2.21 Å. There are two shorter (2.14 Å) and one longer (2.20 Å) Hf–O bond lengths. In the seventh Hf4+ site, Hf4+ is bonded to four N3- and two O2- atoms to form a mixture of corner and edge-sharing HfN4O2 octahedra. The corner-sharing octahedra tilt angles range from 50–59°. There are a spread of Hf–N bond distances ranging from 2.11–2.19 Å. There are one shorter (2.24 Å) and one longer (2.25 Å) Hf–O bond lengths. In the eighth Hf4+ site, Hf4+ is bonded to five N3- and one O2- atom to form a mixture of corner and edge-sharing HfN5O octahedra. The corner-sharing octahedra tilt angles range from 55–58°. There are a spread of Hf–N bond distances ranging from 2.15–2.20 Å. The Hf–O bond length is 2.24 Å. In the ninth Hf4+ site, Hf4+ is bonded to five N3- and one O2- atom to form distorted HfN5O octahedra that share corners with six HfN4O2 octahedra and edges with six HfN3O3 octahedra. The corner-sharing octahedra tilt angles range from 53–59°. There are a spread of Hf–N bond distances ranging from 2.10–2.23 Å. The Hf–O bond length is 2.39 Å. In the tenth Hf4+ site, Hf4+ is bonded to four N3- and two O2- atoms to form a mixture of distorted corner and edge-sharing HfN4O2 octahedra. The corner-sharing octahedra tilt angles range from 53–57°. There are a spread of Hf–N bond distances ranging from 2.10–2.18 Å. There are one shorter (2.20 Å) and one longer (2.29 Å) Hf–O bond lengths. In the eleventh Hf4+ site, Hf4+ is bonded to four N3- and two O2- atoms to form HfN4O2 octahedra that share corners with six HfN4O2 octahedra and edges with six HfN3O3 octahedra. The corner-sharing octahedra tilt angles range from 51–57°. There are a spread of Hf–N bond distances ranging from 2.09–2.18 Å. There are one shorter (2.27 Å) and one longer (2.28 Å) Hf–O bond lengths. In the twelfth Hf4+ site, Hf4+ is bonded to four N3- and two O2- atoms to form distorted HfN4O2 octahedra that share corners with six HfN3O3 octahedra and edges with six HfN4O2 octahedra. The corner-sharing octahedra tilt angles range from 50–53°. There are a spread of Hf–N bond distances ranging from 2.10–2.19 Å. There are one shorter (2.17 Å) and one longer (2.23 Å) Hf–O bond lengths. In the thirteenth Hf4+ site, Hf4+ is bonded to four N3- and two O2- atoms to form distorted HfN4O2 octahedra that share corners with six HfN4O2 octahedra and edges with six HfN3O3 octahedra. The corner-sharing octahedra tilt angles range from 53–57°. There are a spread of Hf–N bond distances ranging from 2.10–2.18 Å. Both Hf–O bond lengths are 2.25 Å. In the fourteenth Hf4+ site, Hf4+ is bonded to four N3- and two O2- atoms to form a mixture of distorted corner and edge-sharing HfN4O2 octahedra. The corner-sharing octahedra tilt angles range from 53–57°. There are a spread of Hf–N bond distances ranging from 2.09–2.21 Å. There are one shorter (2.22 Å) and one longer (2.28 Å) Hf–O bond lengths. In the fifteenth Hf4+ site, Hf4+ is bonded to five N3- and one O2- atom to form a mixture of distorted corner and edge-sharing HfN5O octahedra. The corner-sharing octahedra tilt angles range from 50–56°. There are a spread of Hf–N bond distances ranging from 2.13–2.23 Å. The Hf–O bond length is 2.22 Å. In the sixteenth Hf4+ site, Hf4+ is bonded to six N3- atoms to form a mixture of distorted corner and edge-sharing HfN6 octahedra. The corner-sharing octahedra tilt angles range from 53–57°. There are a spread of Hf–N bond distances ranging from 2.15–2.27 Å. There are sixteen inequivalent N3- sites. In the first N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 tetrahedra that share corners with three NHf4 tetrahedra, corners with two OHf4 trigonal pyramids, corners with seven NHf4 trigonal pyramids, and edges with four OHf4 trigonal pyramids. In the second N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share corners with two NHf4 tetrahedra, corners with four NHf4 trigonal pyramids, corners with six OHf4 trigonal pyramids, an edgeedge with one NHf4 tetrahedra, an edgeedge with one OHf4 trigonal pyramid, and edges with two NHf4 trigonal pyramids. In the third N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share corners with four NHf4 tetrahedra, corners with four NHf4 trigonal pyramids, corners with four OHf4 trigonal pyramids, an edgeedge with one NHf4 trigonal pyramid, and edges with three OHf4 trigonal pyramids. In the fourth N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share corners with five NHf4 tetrahedra, a cornercorner with one OHf4 trigonal pyramid, corners with six NHf4 trigonal pyramids, an edgeedge with one NHf4 trigonal pyramid, and edges with three OHf4 trigonal pyramids. In the fifth N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share corners with three NHf4 tetrahedra, corners with two OHf4 trigonal pyramids, corners with seven NHf4 trigonal pyramids, an edgeedge with one NHf4 trigonal pyramid, and edges with three OHf4 trigonal pyramids. In the sixth N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 tetrahedra that share corners with three NHf4 tetrahedra, corners with two OHf4 trigonal pyramids, corners with seven NHf4 trigonal pyramids, edges with two NHf4 trigonal pyramids, and edges with two OHf4 trigonal pyramids. In the seventh N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 tetrahedra that share corners with three NHf4 tetrahedra, corners with three OHf4 trigonal pyramids, corners with six NHf4 trigonal pyramids, edges with two NHf4 trigonal pyramids, and edges with two OHf4 trigonal pyramids. In the eighth N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share corners with two NHf4 tetrahedra, corners with four NHf4 trigonal pyramids, corners with six OHf4 trigonal pyramids, an edgeedge with one NHf4 tetrahedra, and edges with three NHf4 trigonal pyramids. In the ninth N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share corners with four NHf4 tetrahedra, corners with four NHf4 trigonal pyramids, corners with four OHf4 trigonal pyramids, an edgeedge with one OHf4 trigonal pyramid, and edges with three NHf4 trigonal pyramids. In the tenth N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share corners with three NHf4 tetrahedra, corners with three OHf4 trigonal pyramids, corners with six NHf4 trigonal pyramids, edges with two NHf4 trigonal pyramids, and edges with two OHf4 trigonal pyramids. In the eleventh N3- site, N3- is bonded to four Hf4+ atoms to form NHf4 trigonal pyramids that share corners with five NHf4 trigonal pyramids, corners with seven OHf4 trigonal pyramids, edges with two NHf4 tetrahedra, and edges with two NHf4 trigonal pyramids. In the twelfth N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 tetrahedra that share corners with four NHf4 tetrahedra, corners with four NHf4 trigonal pyramids, corners with four OHf4 trigonal pyramids, edges with two NHf4 trigonal pyramids, and edges with two OHf4 trigonal pyramids. In the thirteenth N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share corners with five NHf4 trigonal pyramids, corners with seven OHf4 trigonal pyramids, edges with three NHf4 tetrahedra, and an edgeedge with one NHf4 trigonal pyramid. In the fourteenth N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 tetrahedra that share corners with three NHf4 tetrahedra, corners with three OHf4 trigonal pyramids, corners with six NHf4 trigonal pyramids, edges with two NHf4 trigonal pyramids, and edges with two OHf4 trigonal pyramids. In the fifteenth N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share corners with two NHf4 tetrahedra, corners with five NHf4 trigonal pyramids, corners with five OHf4 trigonal pyramids, an edgeedge with one NHf4 tetrahedra, an edgeedge with one OHf4 trigonal pyramid, and edges with two NHf4 trigonal pyramids. In the sixteenth N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share corners with five NHf4 tetrahedra, a cornercorner with one OHf4 trigonal pyramid, corners with six NHf4 trigonal pyramids, edges with two NHf4 trigonal pyramids, and edges with two OHf4 trigonal pyramids. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded to four Hf4+ atoms to form distorted OHf4 trigonal pyramids that share corners with five NHf4 trigonal pyramids, corners with seven OHf4 trigonal pyramids, edges with two NHf4 tetrahedra, and edges with two NHf4 trigonal pyramids. In the second O2- site, O2- is bonded to four Hf4+ atoms to form distorted OHf4 trigonal pyramids that share corners with two NHf4 tetrahedra, corners with four NHf4 trigonal pyramids, corners with six OHf4 trigonal pyramids, edges with two NHf4 tetrahedra, and edges with two NHf4 trigonal pyramids. In the third O2- site, O2- is bonded to four Hf4+ atoms to form distorted OHf4 trigonal pyramids that share a cornercorner with one NHf4 tetrahedra, corners with four OHf4 trigonal pyramids, corners with seven NHf4 trigonal pyramids, an edgeedge with one NHf4 tetrahedra, an edgeedge with one OHf4 trigonal pyramid, and edges with two NHf4 trigonal pyramids. In the fourth O2- site, O2- is bonded to four Hf4+ atoms to form distorted OHf4 trigonal pyramids that share corners with two NHf4 tetrahedra, corners with five NHf4 trigonal pyramids, corners with five OHf4 trigonal pyramids, and edges with four NHf4 trigonal pyramids. In the fifth O2-

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Li19(FeAs)20 by Materials Project

Li19(FeAs)20 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are nineteen inequivalent Li1+ sites. In the first Li1+ site, Li1+ is bonded to five As3- atoms to form distorted LiAs5 trigonal bipyramids that share corners with twelve FeAs4 tetrahedra, corners with three LiAs5 trigonal bipyramids, edges with four FeAs4 tetrahedra, and edges with seven LiAs5 trigonal bipyramids. There are a spread of Li–As bond distances ranging from 2.68–2.77 Å. In the second Li1+ site, Li1+ is bonded to five As3- atoms to form distorted LiAs5 trigonal bipyramids that share corners with twelve FeAs4 tetrahedra, corners with four LiAs5 trigonal bipyramids, edges with four FeAs4 tetrahedra, and edges with seven LiAs5 trigonal bipyramids. There are a spread of Li–As bond distances ranging from 2.66–2.76 Å. In the third Li1+ site, Li1+ is bonded to five As3- atoms to form distorted LiAs5 trigonal bipyramids that share corners with twelve FeAs4 tetrahedra, corners with three LiAs5 trigonal bipyramids, edges with four FeAs4 tetrahedra, and edges with seven LiAs5 trigonal bipyramids. There are a spread of Li–As bond distances ranging from 2.68–2.76 Å. In the fourth Li1+ site, Li1+ is bonded to five As3- atoms to form distorted LiAs5 trigonal bipyramids that share corners with twelve FeAs4 tetrahedra, corners with four LiAs5 trigonal bipyramids, edges with four FeAs4 tetrahedra, and edges with eight LiAs5 trigonal bipyramids. There are a spread of Li–As bond distances ranging from 2.70–2.76 Å. In the fifth Li1+ site, Li1+ is bonded to five As3- atoms to form distorted LiAs5 trigonal bipyramids that share corners with twelve FeAs4 tetrahedra, corners with four LiAs5 trigonal bipyramids, edges with four FeAs4 tetrahedra, and edges with seven LiAs5 trigonal bipyramids. There are a spread of Li–As bond distances ranging from 2.67–2.78 Å. In the sixth Li1+ site, Li1+ is bonded to five As3- atoms to form distorted LiAs5 trigonal bipyramids that share corners with twelve FeAs4 tetrahedra, corners with four LiAs5 trigonal bipyramids, edges with four FeAs4 tetrahedra, and edges with eight LiAs5 trigonal bipyramids. There are a spread of Li–As bond distances ranging from 2.70–2.75 Å. In the seventh Li1+ site, Li1+ is bonded to five As3- atoms to form distorted LiAs5 trigonal bipyramids that share corners with twelve FeAs4 tetrahedra, corners with four LiAs5 trigonal bipyramids, edges with four FeAs4 tetrahedra, and edges with eight LiAs5 trigonal bipyramids. There are a spread of Li–As bond distances ranging from 2.70–2.78 Å. In the eighth Li1+ site, Li1+ is bonded to five As3- atoms to form distorted LiAs5 trigonal bipyramids that share corners with twelve FeAs4 tetrahedra, corners with three LiAs5 trigonal bipyramids, edges with four FeAs4 tetrahedra, and edges with seven LiAs5 trigonal bipyramids. There are a spread of Li–As bond distances ranging from 2.68–2.76 Å. In the ninth Li1+ site, Li1+ is bonded to five As3- atoms to form distorted LiAs5 trigonal bipyramids that share corners with twelve FeAs4 tetrahedra, corners with four LiAs5 trigonal bipyramids, edges with four FeAs4 tetrahedra, and edges with eight LiAs5 trigonal bipyramids. There are a spread of Li–As bond distances ranging from 2.69–2.73 Å. In the tenth Li1+ site, Li1+ is bonded to five As3- atoms to form distorted LiAs5 trigonal bipyramids that share corners with twelve FeAs4 tetrahedra, corners with four LiAs5 trigonal bipyramids, edges with four FeAs4 tetrahedra, and edges with eight LiAs5 trigonal bipyramids. There are a spread of Li–As bond distances ranging from 2.67–2.77 Å. In the eleventh Li1+ site, Li1+ is bonded to five As3- atoms to form distorted LiAs5 trigonal bipyramids that share corners with twelve FeAs4 tetrahedra, corners with three LiAs5 trigonal bipyramids, edges with four FeAs4 tetrahedra, and edges with seven LiAs5 trigonal bipyramids. There are a spread of Li–As bond distances ranging from 2.68–2.78 Å. In the twelfth Li1+ site, Li1+ is bonded to five As3- atoms to form distorted LiAs5 trigonal bipyramids that share corners with twelve FeAs4 tetrahedra, corners with four LiAs5 trigonal bipyramids, edges with four FeAs4 tetrahedra, and edges with eight LiAs5 trigonal bipyramids. There are a spread of Li–As bond distances ranging from 2.68–2.78 Å. In the thirteenth Li1+ site, Li1+ is bonded to five As3- atoms to form distorted LiAs5 trigonal bipyramids that share corners with twelve FeAs4 tetrahedra, corners with four LiAs5 trigonal bipyramids, edges with four FeAs4 tetrahedra, and edges with eight LiAs5 trigonal bipyramids. There are a spread of Li–As bond distances ranging from 2.68–2.76 Å. In the fourteenth Li1+ site, Li1+ is bonded to five As3- atoms to form distorted LiAs5 trigonal bipyramids that share corners with twelve FeAs4 tetrahedra, corners with four LiAs5 trigonal bipyramids, edges with four FeAs4 tetrahedra, and edges with seven LiAs5 trigonal bipyramids. There are a spread of Li–As bond distances ranging from 2.67–2.78 Å. In the fifteenth Li1+ site, Li1+ is bonded to five As3- atoms to form distorted LiAs5 trigonal bipyramids that share corners with twelve FeAs4 tetrahedra, corners with four LiAs5 trigonal bipyramids, edges with four FeAs4 tetrahedra, and edges with eight LiAs5 trigonal bipyramids. There are a spread of Li–As bond distances ranging from 2.68–2.76 Å. In the sixteenth Li1+ site, Li1+ is bonded to five As3- atoms to form distorted LiAs5 trigonal bipyramids that share corners with twelve FeAs4 tetrahedra, corners with four LiAs5 trigonal bipyramids, edges with four FeAs4 tetrahedra, and edges with seven LiAs5 trigonal bipyramids. There are a spread of Li–As bond distances ranging from 2.66–2.76 Å. In the seventeenth Li1+ site, Li1+ is bonded to five As3- atoms to form distorted LiAs5 trigonal bipyramids that share corners with twelve FeAs4 tetrahedra, corners with four LiAs5 trigonal bipyramids, edges with four FeAs4 tetrahedra, and edges with eight LiAs5 trigonal bipyramids. There are a spread of Li–As bond distances ranging from 2.69–2.78 Å. In the eighteenth Li1+ site, Li1+ is bonded to five As3- atoms to form distorted LiAs5 trigonal bipyramids that share corners with twelve FeAs4 tetrahedra, corners with four LiAs5 trigonal bipyramids, edges with four FeAs4 tetrahedra, and edges with eight LiAs5 trigonal bipyramids. There are a spread of Li–As bond distances ranging from 2.68–2.74 Å. In the nineteenth Li1+ site, Li1+ is bonded to five As3- atoms to form distorted LiAs5 trigonal bipyramids that share corners with twelve FeAs4 tetrahedra, corners with four LiAs5 trigonal bipyramids, edges with four FeAs4 tetrahedra, and edges with eight LiAs5 trigonal bipyramids. There are a spread of Li–As bond distances ranging from 2.70–2.78 Å. There are twenty inequivalent Fe+2.05+ sites. In the first Fe+2.05+ site, Fe+2.05+ is bonded to four As3- atoms to form FeAs4 tetrahedra that share corners with four FeAs4 tetrahedra, corners with eleven LiAs5 trigonal bipyramids, edges with four FeAs4 tetrahedra, and edges with four LiAs5 trigonal bipyramids. There are a spread of Fe–As bond distances ranging from 2.34–2.38 Å. In the second Fe+2.05+ site, Fe+2.05+ is bonded to four As3- atoms to form FeAs4 tetrahedra that share corners with four FeAs4 tetrahedra, corners with twelve LiAs5 trigonal bipyramids, edges with four FeAs4 tetrahedra, and edges with four LiAs5 trigonal bipyramids. There are a spread of Fe–As bond distances ranging from 2.36–2.39 Å. In the third Fe+2.05+ site, Fe+2.05+ is bonded to four As3- atoms to form FeAs4 tetrahedra that share corners with four FeAs4 tetrahedra, corners with eleven LiAs5 trigonal bipyramids, edges with four FeAs4 tetrahedra, and edges with four LiAs5 trigonal bipyramids. There are a spread of Fe–As bond distances ranging from 2.37–2.39 Å. In the fourth Fe+2.05+ site, Fe+2.05+ is bonded to four As3- atoms to form FeAs4 tetrahedra that share corners with four FeAs4 tetrahedra, corners with eleven LiAs5 trigonal bipyramids, edges with four FeAs4 tetrahedra, and edges with four LiAs5 trigonal bipyramids. There are a spread of Fe–As bond distances ranging from 2.37–2.39 Å. In the fifth Fe+2.05+ site, Fe+2.05+ is bonded to four As3- atoms to form FeAs4 tetrahedra that share corners with four FeAs4 tetrahedra, corners with twelve LiAs5 trigonal bipyramids, edges with four FeAs4 tetrahedra, and edges with three LiAs5 trigonal bipyramids. There are a spread of Fe–As bond distances ranging from 2.35–2.38 Å. In the sixth Fe+2.05+ site, Fe+2.05+ is bonded to four As3- atoms to form FeAs4 tetrahedra that share corners with four FeAs4 tetrahedra, corners with twelve LiAs5 trigonal bipyramids, edges with four FeAs4 tetrahedra, and edges with four LiAs5 trigonal bipyramids. All Fe–As bond lengths are 2.39 Å. In the seventh Fe+2.05+ site, Fe+2.05+ is bonded to four As3- atoms to form FeAs4 tetrahedra that share corners with four FeAs4 tetrahedra, corners with ten LiAs5 trigonal bipyramids, edges with four FeAs4 tetrahedra, and edges with four LiAs5 trigonal bipyramids. There are two shorter (2.35 Å) and two longer (2.39 Å) Fe–As bond lengths. In the eighth Fe+2.05+ site, Fe+2.05+ is bonded to four As3- atoms to form FeAs4 tetrahedra that share corners with four FeAs4 tetrahedra, corners with twelve LiAs5 trigonal bipyramids, edges with four FeAs4 tetrahedra, and edges with four LiAs5 trigonal bipyramids. There are a spread of Fe–As bond distances ranging from 2.37–2.40 Å. In the ninth Fe+2.05+ site, Fe+2.05+ is bonded to four As3- atoms to form FeAs4 tetrahedra that share corners with four FeAs4 tetrahedra, corners with eleven LiAs5 trigonal bipyramids, edges with four FeAs4 tetrahedra, and edges with four LiAs5 trigonal bipyramids. There are a spread of Fe–As bond distances ranging from 2.35–2.39 Å. In the tenth Fe+2.05+ site, Fe+2.05+ is bonded to four As3- atoms to form FeAs4 tetrahedra that share corners with four FeAs4 tetrahedra, corners with twelve LiAs5 trigonal bipyramids, edges with four FeAs4 tetrahedra, and edges with four LiAs5 trigonal bipyramids. There are a spread of Fe–As bond distances ranging from 2.36–2.39 Å. In the eleventh Fe+2.05+ site, Fe+2.05+ is bonded to four As3- atoms to form FeAs4 tetrahedra that share corners with four FeAs4 tetrahedra, corners with eleven LiAs5 trigonal bipyramids, edges with four FeAs4 tetrahedra, and edges with four LiAs5 trigonal bipyramids. There are a spread of Fe–As bond distances ranging from 2.37–2.39 Å. In the twelfth Fe+2.05+ site, Fe+2.05+ is bonded to four As3- atoms to form FeAs4 tetrahedra that share corners with four FeAs4 tetrahedra, corners with eleven LiAs5 trigonal bipyramids, edges with four FeAs4 tetrahedra, and edges with four LiAs5 trigonal bipyramids. There are a spread of Fe–As bond distances ranging from 2.35–2.39 Å. In the thirteenth Fe+2.05+ site, Fe+2.05+ is bonded to four As3- atoms to form FeAs4 tetrahedra that share corners with four FeAs4 tetrahedra, corners with twelve LiAs5 trigonal bipyramids, edges with four FeAs4 tetrahedra, and edges with four LiAs5 trigonal bipyramids. There are a spread of Fe–As bond distances ranging from 2.37–2.40 Å. In the fourteenth Fe+2.05+ site, Fe+2.05+ is bonded to four As3- atoms to form FeAs4 tetrahedra that share corners with four FeAs4 tetrahedra, corners with eleven LiAs5 trigonal bipyramids, edges with four FeAs4 tetrahedra, and edges with four LiAs5 trigonal bipyramids. There are a spread of Fe–As bond distances ranging from 2.35–2.40 Å. In the fifteenth Fe+2.05+ site, Fe+2.05+ is bonded to four As3- atoms to form FeAs4 tetrahedra that share corners with four FeAs4 tetrahedra, corners with twelve LiAs5 trigonal bipyramids, edges with four FeAs4 tetrahedra, and edges with three LiAs5 trigonal bipyramids. There are a spread of Fe–As bond distances ranging from 2.36–2.39 Å. In the sixteenth Fe+2.05+ site, Fe+2.05+ is bonded to four As3- atoms to form FeAs4 tetrahedra that share corners with four FeAs4 tetrahedra, corners with

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Hf2N2O by Materials Project

Hf2ON2 is Ilmenite-like structured and crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are sixteen inequivalent Hf4+ sites. In the first Hf4+ site, Hf4+ is bonded to three N3- and three O2- atoms to form distorted HfN3O3 octahedra that share corners with six HfN3O3 octahedra and edges with six HfN4O2 octahedra. The corner-sharing octahedra tilt angles range from 52–55°. There are a spread of Hf–N bond distances ranging from 2.07–2.12 Å. There are a spread of Hf–O bond distances ranging from 2.17–2.28 Å. In the second Hf4+ site, Hf4+ is bonded to four N3- and two O2- atoms to form a mixture of corner and edge-sharing HfN4O2 octahedra. The corner-sharing octahedra tilt angles range from 53–58°. There are a spread of Hf–N bond distances ranging from 2.11–2.17 Å. There are one shorter (2.25 Å) and one longer (2.26 Å) Hf–O bond lengths. In the third Hf4+ site, Hf4+ is bonded to three N3- and three O2- atoms to form distorted HfN3O3 octahedra that share corners with six HfN4O2 octahedra and edges with six HfN3O3 octahedra. The corner-sharing octahedra tilt angles range from 52–55°. There are one shorter (2.08 Å) and two longer (2.13 Å) Hf–N bond lengths. There are a spread of Hf–O bond distances ranging from 2.11–2.32 Å. In the fourth Hf4+ site, Hf4+ is bonded to four N3- and two O2- atoms to form distorted HfN4O2 octahedra that share corners with six HfN4O2 octahedra and edges with six HfN3O3 octahedra. The corner-sharing octahedra tilt angles range from 52–54°. There are a spread of Hf–N bond distances ranging from 2.12–2.25 Å. There are one shorter (2.13 Å) and one longer (2.24 Å) Hf–O bond lengths. In the fifth Hf4+ site, Hf4+ is bonded to four N3- and two O2- atoms to form distorted HfN4O2 octahedra that share corners with six HfN4O2 octahedra and edges with six HfN3O3 octahedra. The corner-sharing octahedra tilt angles range from 52–57°. There are a spread of Hf–N bond distances ranging from 2.10–2.19 Å. There are one shorter (2.22 Å) and one longer (2.27 Å) Hf–O bond lengths. In the sixth Hf4+ site, Hf4+ is bonded to three N3- and three O2- atoms to form distorted HfN3O3 octahedra that share corners with six HfN3O3 octahedra and edges with six HfN4O2 octahedra. The corner-sharing octahedra tilt angles range from 50–56°. There are a spread of Hf–N bond distances ranging from 2.08–2.16 Å. There are a spread of Hf–O bond distances ranging from 2.16–2.22 Å. In the seventh Hf4+ site, Hf4+ is bonded to three N3- and three O2- atoms to form HfN3O3 octahedra that share corners with six HfN4O2 octahedra and edges with six HfN3O3 octahedra. The corner-sharing octahedra tilt angles range from 51–58°. There are a spread of Hf–N bond distances ranging from 2.07–2.17 Å. There are a spread of Hf–O bond distances ranging from 2.14–2.28 Å. In the eighth Hf4+ site, Hf4+ is bonded to four N3- and two O2- atoms to form distorted HfN4O2 octahedra that share corners with six HfN4O2 octahedra and edges with six HfN3O3 octahedra. The corner-sharing octahedra tilt angles range from 50–57°. There are a spread of Hf–N bond distances ranging from 2.14–2.23 Å. There are one shorter (2.15 Å) and one longer (2.16 Å) Hf–O bond lengths. In the ninth Hf4+ site, Hf4+ is bonded to five N3- and one O2- atom to form distorted HfN5O octahedra that share corners with six HfN4O2 octahedra and edges with six HfN3O3 octahedra. The corner-sharing octahedra tilt angles range from 53–58°. There are a spread of Hf–N bond distances ranging from 2.10–2.23 Å. The Hf–O bond length is 2.36 Å. In the tenth Hf4+ site, Hf4+ is bonded to four N3- and two O2- atoms to form a mixture of corner and edge-sharing HfN4O2 octahedra. The corner-sharing octahedra tilt angles range from 50–59°. There are a spread of Hf–N bond distances ranging from 2.09–2.20 Å. There are one shorter (2.24 Å) and one longer (2.26 Å) Hf–O bond lengths. In the eleventh Hf4+ site, Hf4+ is bonded to four N3- and two O2- atoms to form a mixture of distorted corner and edge-sharing HfN4O2 octahedra. The corner-sharing octahedra tilt angles range from 52–58°. There are a spread of Hf–N bond distances ranging from 2.08–2.24 Å. There are one shorter (2.21 Å) and one longer (2.26 Å) Hf–O bond lengths. In the twelfth Hf4+ site, Hf4+ is bonded to five N3- and one O2- atom to form a mixture of distorted corner and edge-sharing HfN5O octahedra. The corner-sharing octahedra tilt angles range from 52–56°. There are a spread of Hf–N bond distances ranging from 2.13–2.21 Å. The Hf–O bond length is 2.24 Å. In the thirteenth Hf4+ site, Hf4+ is bonded to three N3- and three O2- atoms to form distorted HfN3O3 octahedra that share corners with six HfN3O3 octahedra and edges with six HfN4O2 octahedra. The corner-sharing octahedra tilt angles range from 50–54°. There are two shorter (2.14 Å) and one longer (2.15 Å) Hf–N bond lengths. There are a spread of Hf–O bond distances ranging from 2.11–2.20 Å. In the fourteenth Hf4+ site, Hf4+ is bonded to six N3- atoms to form distorted HfN6 octahedra that share corners with six HfN3O3 octahedra and edges with six HfN4O2 octahedra. The corner-sharing octahedra tilt angles range from 52–56°. There are a spread of Hf–N bond distances ranging from 2.14–2.26 Å. In the fifteenth Hf4+ site, Hf4+ is bonded to five N3- and one O2- atom to form HfN5O octahedra that share corners with six HfN3O3 octahedra and edges with six HfN4O2 octahedra. The corner-sharing octahedra tilt angles range from 53–59°. There are a spread of Hf–N bond distances ranging from 2.09–2.22 Å. The Hf–O bond length is 2.30 Å. In the sixteenth Hf4+ site, Hf4+ is bonded to four N3- and two O2- atoms to form distorted HfN4O2 octahedra that share corners with six HfN3O3 octahedra and edges with six HfN4O2 octahedra. The corner-sharing octahedra tilt angles range from 52–59°. There are a spread of Hf–N bond distances ranging from 2.11–2.21 Å. There are one shorter (2.19 Å) and one longer (2.30 Å) Hf–O bond lengths. There are sixteen inequivalent N3- sites. In the first N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share a cornercorner with one NHf4 tetrahedra, corners with four OHf4 trigonal pyramids, corners with seven NHf4 trigonal pyramids, an edgeedge with one NHf4 tetrahedra, an edgeedge with one NHf4 trigonal pyramid, and edges with two OHf4 trigonal pyramids. In the second N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 tetrahedra that share a cornercorner with one NHf4 tetrahedra, corners with four OHf4 trigonal pyramids, corners with seven NHf4 trigonal pyramids, an edgeedge with one NHf4 trigonal pyramid, and edges with three OHf4 trigonal pyramids. In the third N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 tetrahedra that share a cornercorner with one NHf4 tetrahedra, corners with four OHf4 trigonal pyramids, corners with seven NHf4 trigonal pyramids, edges with two NHf4 trigonal pyramids, and edges with two OHf4 trigonal pyramids. In the fourth N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share a cornercorner with one NHf4 tetrahedra, corners with five OHf4 trigonal pyramids, corners with six NHf4 trigonal pyramids, an edgeedge with one NHf4 tetrahedra, an edgeedge with one NHf4 trigonal pyramid, and edges with two OHf4 trigonal pyramids. In the fifth N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 tetrahedra that share corners with five OHf4 trigonal pyramids, corners with seven NHf4 trigonal pyramids, edges with two NHf4 trigonal pyramids, and edges with two OHf4 trigonal pyramids. In the sixth N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share a cornercorner with one NHf4 tetrahedra, corners with five OHf4 trigonal pyramids, corners with six NHf4 trigonal pyramids, an edgeedge with one OHf4 trigonal pyramid, and edges with three NHf4 trigonal pyramids. In the seventh N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share corners with two NHf4 tetrahedra, corners with four OHf4 trigonal pyramids, corners with six NHf4 trigonal pyramids, an edgeedge with one OHf4 trigonal pyramid, and edges with three NHf4 trigonal pyramids. In the eighth N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share corners with two NHf4 tetrahedra, corners with four OHf4 trigonal pyramids, corners with six NHf4 trigonal pyramids, edges with two NHf4 trigonal pyramids, and edges with two OHf4 trigonal pyramids. In the ninth N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share corners with two NHf4 tetrahedra, corners with three OHf4 trigonal pyramids, corners with seven NHf4 trigonal pyramids, an edgeedge with one NHf4 trigonal pyramid, and edges with three OHf4 trigonal pyramids. In the tenth N3- site, N3- is bonded to four Hf4+ atoms to form NHf4 trigonal pyramids that share corners with two NHf4 tetrahedra, corners with four OHf4 trigonal pyramids, corners with six NHf4 trigonal pyramids, and edges with four NHf4 trigonal pyramids. In the eleventh N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share corners with two NHf4 tetrahedra, corners with three OHf4 trigonal pyramids, corners with seven NHf4 trigonal pyramids, edges with two NHf4 trigonal pyramids, and edges with two OHf4 trigonal pyramids. In the twelfth N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share corners with three NHf4 tetrahedra, corners with three OHf4 trigonal pyramids, corners with six NHf4 trigonal pyramids, an edgeedge with one OHf4 trigonal pyramid, and edges with three NHf4 trigonal pyramids. In the thirteenth N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share a cornercorner with one NHf4 tetrahedra, corners with four OHf4 trigonal pyramids, corners with seven NHf4 trigonal pyramids, an edgeedge with one OHf4 trigonal pyramid, and edges with three NHf4 trigonal pyramids. In the fourteenth N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share a cornercorner with one NHf4 tetrahedra, corners with four OHf4 trigonal pyramids, corners with seven NHf4 trigonal pyramids, an edgeedge with one NHf4 tetrahedra, an edgeedge with one OHf4 trigonal pyramid, and edges with two NHf4 trigonal pyramids. In the fifteenth N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share corners with five OHf4 trigonal pyramids, corners with seven NHf4 trigonal pyramids, edges with two NHf4 tetrahedra, an edgeedge with one NHf4 trigonal pyramid, and an edgeedge with one OHf4 trigonal pyramid. In the sixteenth N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share corners with three NHf4 tetrahedra, corners with three OHf4 trigonal pyramids, corners with six NHf4 trigonal pyramids, edges with two NHf4 trigonal pyramids, and edges with two OHf4 trigonal pyramids. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded to four Hf4+ atoms to form distorted OHf4 trigonal pyramids that share corners with two NHf4 tetrahedra, corners with four OHf4 trigonal pyramids, corners with six NHf4 trigonal pyramids, an edgeedge with one NHf4 tetrahedra, and edges with three NHf4 trigonal pyramids. In the second O2- site, O2- is bonded to four Hf4+ atoms to form distorted OHf4 trigonal pyramids that share corners with two NHf4 tetrahedra, corners with four OHf4 trigonal pyramids, corners with six NHf4 trigonal pyramids, an edgeedge with one NHf4 tetrahedra, an edgeedge with one NHf4 trigonal pyramid, and edges with two OHf4 trigonal pyramids. In the third O2- site, O2- is bonded to four Hf4+ atoms to form distorted OHf4 trigonal pyramids that share corners with two NHf4 tetrahedra, corners with four OHf4 trigonal pyramids,

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Zr2N2O by Materials Project

Zr2ON2 is Ilmenite-like structured and crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are sixteen inequivalent Zr4+ sites. In the first Zr4+ site, Zr4+ is bonded to four N3- and two O2- atoms to form ZrN4O2 octahedra that share corners with six ZrN4O2 octahedra and edges with six ZrN3O3 octahedra. The corner-sharing octahedra tilt angles range from 53–57°. There are a spread of Zr–N bond distances ranging from 2.12–2.22 Å. There are one shorter (2.31 Å) and one longer (2.32 Å) Zr–O bond lengths. In the second Zr4+ site, Zr4+ is bonded to three N3- and three O2- atoms to form a mixture of distorted edge and corner-sharing ZrN3O3 octahedra. The corner-sharing octahedra tilt angles range from 51–55°. There are a spread of Zr–N bond distances ranging from 2.10–2.19 Å. There are a spread of Zr–O bond distances ranging from 2.17–2.35 Å. In the third Zr4+ site, Zr4+ is bonded to four N3- and two O2- atoms to form distorted ZrN4O2 octahedra that share corners with six ZrN3O3 octahedra and edges with six ZrN4O2 octahedra. The corner-sharing octahedra tilt angles range from 52–58°. There are a spread of Zr–N bond distances ranging from 2.17–2.30 Å. There are one shorter (2.17 Å) and one longer (2.28 Å) Zr–O bond lengths. In the fourth Zr4+ site, Zr4+ is bonded to four N3- and two O2- atoms to form distorted ZrN4O2 octahedra that share corners with six ZrN4O2 octahedra and edges with six ZrN3O3 octahedra. The corner-sharing octahedra tilt angles range from 51–57°. There are a spread of Zr–N bond distances ranging from 2.17–2.27 Å. There are one shorter (2.18 Å) and one longer (2.25 Å) Zr–O bond lengths. In the fifth Zr4+ site, Zr4+ is bonded to three N3- and three O2- atoms to form a mixture of distorted edge and corner-sharing ZrN3O3 octahedra. The corner-sharing octahedra tilt angles range from 52–57°. There are a spread of Zr–N bond distances ranging from 2.10–2.23 Å. There are a spread of Zr–O bond distances ranging from 2.16–2.27 Å. In the sixth Zr4+ site, Zr4+ is bonded to four N3- and two O2- atoms to form a mixture of distorted edge and corner-sharing ZrN4O2 octahedra. The corner-sharing octahedra tilt angles range from 50–59°. There are a spread of Zr–N bond distances ranging from 2.14–2.25 Å. There are one shorter (2.25 Å) and one longer (2.27 Å) Zr–O bond lengths. In the seventh Zr4+ site, Zr4+ is bonded to three N3- and three O2- atoms to form a mixture of distorted edge and corner-sharing ZrN3O3 octahedra. The corner-sharing octahedra tilt angles range from 50–56°. There are a spread of Zr–N bond distances ranging from 2.14–2.27 Å. There are a spread of Zr–O bond distances ranging from 2.16–2.25 Å. In the eighth Zr4+ site, Zr4+ is bonded to four N3- and two O2- atoms to form ZrN4O2 octahedra that share corners with six ZrN4O2 octahedra and edges with six ZrN3O3 octahedra. The corner-sharing octahedra tilt angles range from 53–57°. There are a spread of Zr–N bond distances ranging from 2.14–2.25 Å. There are one shorter (2.28 Å) and one longer (2.31 Å) Zr–O bond lengths. In the ninth Zr4+ site, Zr4+ is bonded to five N3- and one O2- atom to form ZrN5O octahedra that share corners with six ZrN3O3 octahedra and edges with six ZrN4O2 octahedra. The corner-sharing octahedra tilt angles range from 52–59°. There are a spread of Zr–N bond distances ranging from 2.14–2.28 Å. The Zr–O bond length is 2.33 Å. In the tenth Zr4+ site, Zr4+ is bonded to three N3- and three O2- atoms to form ZrN3O3 octahedra that share corners with six ZrN3O3 octahedra and edges with six ZrN4O2 octahedra. The corner-sharing octahedra tilt angles range from 49–57°. There are a spread of Zr–N bond distances ranging from 2.11–2.16 Å. There are a spread of Zr–O bond distances ranging from 2.23–2.29 Å. In the eleventh Zr4+ site, Zr4+ is bonded to five N3- and one O2- atom to form a mixture of distorted edge and corner-sharing ZrN5O octahedra. The corner-sharing octahedra tilt angles range from 53–57°. There are a spread of Zr–N bond distances ranging from 2.14–2.25 Å. The Zr–O bond length is 2.32 Å. In the twelfth Zr4+ site, Zr4+ is bonded to five N3- and one O2- atom to form distorted ZrN5O octahedra that share corners with six ZrN3O3 octahedra and edges with six ZrN4O2 octahedra. The corner-sharing octahedra tilt angles range from 52–57°. There are a spread of Zr–N bond distances ranging from 2.16–2.30 Å. The Zr–O bond length is 2.26 Å. In the thirteenth Zr4+ site, Zr4+ is bonded to four N3- and two O2- atoms to form distorted ZrN4O2 octahedra that share corners with six ZrN4O2 octahedra and edges with six ZrN3O3 octahedra. The corner-sharing octahedra tilt angles range from 52–57°. There are a spread of Zr–N bond distances ranging from 2.12–2.25 Å. There are one shorter (2.21 Å) and one longer (2.33 Å) Zr–O bond lengths. In the fourteenth Zr4+ site, Zr4+ is bonded to four N3- and two O2- atoms to form distorted ZrN4O2 octahedra that share corners with six ZrN4O2 octahedra and edges with six ZrN3O3 octahedra. The corner-sharing octahedra tilt angles range from 49–54°. There are a spread of Zr–N bond distances ranging from 2.15–2.25 Å. There are one shorter (2.17 Å) and one longer (2.23 Å) Zr–O bond lengths. In the fifteenth Zr4+ site, Zr4+ is bonded to four N3- and two O2- atoms to form distorted ZrN4O2 octahedra that share corners with six ZrN3O3 octahedra and edges with six ZrN4O2 octahedra. The corner-sharing octahedra tilt angles range from 52–55°. There are a spread of Zr–N bond distances ranging from 2.18–2.25 Å. There are one shorter (2.19 Å) and one longer (2.20 Å) Zr–O bond lengths. In the sixteenth Zr4+ site, Zr4+ is bonded to five N3- and one O2- atom to form a mixture of distorted edge and corner-sharing ZrN5O octahedra. The corner-sharing octahedra tilt angles range from 51–58°. There are a spread of Zr–N bond distances ranging from 2.14–2.26 Å. The Zr–O bond length is 2.31 Å. There are sixteen inequivalent N3- sites. In the first N3- site, N3- is bonded to four Zr4+ atoms to form distorted NZr4 trigonal pyramids that share a cornercorner with one OZr4 tetrahedra, corners with four OZr4 trigonal pyramids, corners with seven NZr4 trigonal pyramids, edges with two NZr4 trigonal pyramids, and edges with two OZr4 trigonal pyramids. In the second N3- site, N3- is bonded to four Zr4+ atoms to form distorted NZr4 trigonal pyramids that share a cornercorner with one NZr4 tetrahedra, a cornercorner with one OZr4 tetrahedra, corners with four OZr4 trigonal pyramids, corners with six NZr4 trigonal pyramids, edges with two NZr4 trigonal pyramids, and edges with two OZr4 trigonal pyramids. In the third N3- site, N3- is bonded to four Zr4+ atoms to form distorted NZr4 trigonal pyramids that share corners with three OZr4 trigonal pyramids, corners with nine NZr4 trigonal pyramids, an edgeedge with one OZr4 tetrahedra, an edgeedge with one NZr4 trigonal pyramid, and edges with two OZr4 trigonal pyramids. In the fourth N3- site, N3- is bonded to four Zr4+ atoms to form distorted NZr4 trigonal pyramids that share corners with three OZr4 trigonal pyramids, corners with nine NZr4 trigonal pyramids, edges with two NZr4 trigonal pyramids, and edges with two OZr4 trigonal pyramids. In the fifth N3- site, N3- is bonded to four Zr4+ atoms to form distorted NZr4 trigonal pyramids that share a cornercorner with one NZr4 tetrahedra, corners with four OZr4 trigonal pyramids, corners with seven NZr4 trigonal pyramids, edges with two NZr4 trigonal pyramids, and edges with two OZr4 trigonal pyramids. In the sixth N3- site, N3- is bonded to four Zr4+ atoms to form distorted NZr4 trigonal pyramids that share a cornercorner with one NZr4 tetrahedra, a cornercorner with one OZr4 tetrahedra, corners with three OZr4 trigonal pyramids, corners with seven NZr4 trigonal pyramids, an edgeedge with one OZr4 trigonal pyramid, and edges with three NZr4 trigonal pyramids. In the seventh N3- site, N3- is bonded to four Zr4+ atoms to form distorted NZr4 trigonal pyramids that share a cornercorner with one NZr4 tetrahedra, a cornercorner with one OZr4 tetrahedra, corners with four OZr4 trigonal pyramids, corners with six NZr4 trigonal pyramids, edges with two NZr4 trigonal pyramids, and edges with two OZr4 trigonal pyramids. In the eighth N3- site, N3- is bonded to four Zr4+ atoms to form distorted NZr4 trigonal pyramids that share a cornercorner with one NZr4 tetrahedra, a cornercorner with one OZr4 tetrahedra, corners with three OZr4 trigonal pyramids, corners with seven NZr4 trigonal pyramids, an edgeedge with one NZr4 trigonal pyramid, and edges with three OZr4 trigonal pyramids. In the ninth N3- site, N3- is bonded to four Zr4+ atoms to form NZr4 trigonal pyramids that share a cornercorner with one NZr4 tetrahedra, a cornercorner with one OZr4 tetrahedra, corners with four OZr4 trigonal pyramids, corners with six NZr4 trigonal pyramids, and edges with four NZr4 trigonal pyramids. In the tenth N3- site, N3- is bonded to four Zr4+ atoms to form distorted NZr4 trigonal pyramids that share a cornercorner with one OZr4 tetrahedra, corners with three OZr4 trigonal pyramids, corners with eight NZr4 trigonal pyramids, an edgeedge with one NZr4 tetrahedra, an edgeedge with one OZr4 trigonal pyramid, and edges with two NZr4 trigonal pyramids. In the eleventh N3- site, N3- is bonded to four Zr4+ atoms to form distorted NZr4 trigonal pyramids that share a cornercorner with one NZr4 tetrahedra, corners with three OZr4 trigonal pyramids, corners with eight NZr4 trigonal pyramids, an edgeedge with one OZr4 tetrahedra, an edgeedge with one NZr4 trigonal pyramid, and edges with two OZr4 trigonal pyramids. In the twelfth N3- site, N3- is bonded to four Zr4+ atoms to form distorted NZr4 trigonal pyramids that share a cornercorner with one NZr4 tetrahedra, corners with four OZr4 trigonal pyramids, corners with seven NZr4 trigonal pyramids, an edgeedge with one OZr4 trigonal pyramid, and edges with three NZr4 trigonal pyramids. In the thirteenth N3- site, N3- is bonded to four Zr4+ atoms to form distorted NZr4 trigonal pyramids that share corners with four OZr4 trigonal pyramids, corners with eight NZr4 trigonal pyramids, edges with two NZr4 trigonal pyramids, and edges with two OZr4 trigonal pyramids. In the fourteenth N3- site, N3- is bonded to four Zr4+ atoms to form distorted NZr4 tetrahedra that share corners with three OZr4 trigonal pyramids, corners with nine NZr4 trigonal pyramids, an edgeedge with one OZr4 tetrahedra, an edgeedge with one OZr4 trigonal pyramid, and edges with two NZr4 trigonal pyramids. In the fifteenth N3- site, N3- is bonded to four Zr4+ atoms to form distorted NZr4 trigonal pyramids that share a cornercorner with one OZr4 tetrahedra, corners with four OZr4 trigonal pyramids, corners with seven NZr4 trigonal pyramids, an edgeedge with one NZr4 tetrahedra, an edgeedge with one OZr4 trigonal pyramid, and edges with two NZr4 trigonal pyramids. In the sixteenth N3- site, N3- is bonded to four Zr4+ atoms to form NZr4 trigonal pyramids that share a cornercorner with one NZr4 tetrahedra, corners with three OZr4 trigonal pyramids, corners with eight NZr4 trigonal pyramids, an edgeedge with one OZr4 trigonal pyramid, and edges with three NZr4 trigonal pyramids. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded to four Zr4+ atoms to form distorted OZr4 trigonal pyramids that share a cornercorner with one NZr4 tetrahedra, corners with three OZr4 trigonal pyramids, corners with eight NZr4 trigonal pyramids, an edgeedge with one OZr4 trigonal pyramid, and edges with three NZr4 trigonal pyramids. In the second O2- site, O2- is bonded to four Zr4+ atoms to form distorted OZr4 trigonal pyramids that share a cornercorner with one NZr4 tetrahedra, a cornercorner with one OZr4 tetrahedra, corners with three OZr4 trigonal pyramids, corners with seven NZr4 trigonal pyramids, and edges with four NZr4 trigonal pyramids. In the third O2- site, O2- i

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ti2N2O by Materials Project

Ti2N2O is Ilmenite-like structured and crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are sixteen inequivalent Ti4+ sites. In the first Ti4+ site, Ti4+ is bonded to three N3- and three O2- atoms to form TiN3O3 octahedra that share corners with five TiN4O2 octahedra, a cornercorner with one TiN3O3 pentagonal pyramid, edges with five TiN3O3 octahedra, and an edgeedge with one TiN3O3 pentagonal pyramid. The corner-sharing octahedra tilt angles range from 48–55°. There are a spread of Ti–N bond distances ranging from 1.96–2.00 Å. There are a spread of Ti–O bond distances ranging from 2.07–2.12 Å. In the second Ti4+ site, Ti4+ is bonded to three N3- and three O2- atoms to form a mixture of distorted edge and corner-sharing TiN3O3 pentagonal pyramids. The corner-sharing octahedra tilt angles range from 50–52°. There are a spread of Ti–N bond distances ranging from 2.00–2.06 Å. There are a spread of Ti–O bond distances ranging from 1.99–2.09 Å. In the third Ti4+ site, Ti4+ is bonded to three N3- and three O2- atoms to form distorted TiN3O3 octahedra that share corners with six TiN5O octahedra, edges with four TiN3O3 octahedra, and edges with two TiN3O3 pentagonal pyramids. The corner-sharing octahedra tilt angles range from 51–56°. There are a spread of Ti–N bond distances ranging from 1.96–2.00 Å. There are a spread of Ti–O bond distances ranging from 2.09–2.13 Å. In the fourth Ti4+ site, Ti4+ is bonded to four N3- and two O2- atoms to form distorted TiN4O2 octahedra that share corners with four TiN3O3 octahedra, corners with two TiN3O3 pentagonal pyramids, and edges with six TiN5O octahedra. The corner-sharing octahedra tilt angles range from 49–53°. There are a spread of Ti–N bond distances ranging from 2.00–2.09 Å. There are one shorter (2.02 Å) and one longer (2.05 Å) Ti–O bond lengths. In the fifth Ti4+ site, Ti4+ is bonded to three N3- and three O2- atoms to form distorted TiN3O3 pentagonal pyramids that share corners with six TiN4O2 octahedra and edges with six TiN3O3 octahedra. The corner-sharing octahedra tilt angles range from 45–57°. There are a spread of Ti–N bond distances ranging from 1.91–2.05 Å. There are a spread of Ti–O bond distances ranging from 2.02–2.18 Å. In the sixth Ti4+ site, Ti4+ is bonded to five N3- and one O2- atom to form TiN5O octahedra that share corners with five TiN3O3 octahedra, a cornercorner with one TiN3O3 pentagonal pyramid, edges with five TiN4O2 octahedra, and an edgeedge with one TiN3O3 pentagonal pyramid. The corner-sharing octahedra tilt angles range from 51–58°. There are a spread of Ti–N bond distances ranging from 1.94–2.10 Å. The Ti–O bond length is 2.22 Å. In the seventh Ti4+ site, Ti4+ is bonded to three N3- and three O2- atoms to form a mixture of distorted edge and corner-sharing TiN3O3 octahedra. The corner-sharing octahedra tilt angles range from 48–54°. There are a spread of Ti–N bond distances ranging from 1.96–2.10 Å. There are one shorter (1.99 Å) and two longer (2.11 Å) Ti–O bond lengths. In the eighth Ti4+ site, Ti4+ is bonded to four N3- and two O2- atoms to form distorted TiN4O2 octahedra that share corners with four TiN4O2 octahedra, corners with two TiN3O3 pentagonal pyramids, and edges with six TiN3O3 octahedra. The corner-sharing octahedra tilt angles range from 51–52°. There are one shorter (2.03 Å) and three longer (2.04 Å) Ti–N bond lengths. There are one shorter (2.04 Å) and one longer (2.05 Å) Ti–O bond lengths. In the ninth Ti4+ site, Ti4+ is bonded to four N3- and two O2- atoms to form TiN4O2 octahedra that share corners with five TiN4O2 octahedra, a cornercorner with one TiN3O3 pentagonal pyramid, edges with five TiN3O3 octahedra, and an edgeedge with one TiN3O3 pentagonal pyramid. The corner-sharing octahedra tilt angles range from 51–57°. There are a spread of Ti–N bond distances ranging from 1.93–2.06 Å. There are one shorter (2.15 Å) and one longer (2.18 Å) Ti–O bond lengths. In the tenth Ti4+ site, Ti4+ is bonded to four N3- and two O2- atoms to form TiN4O2 octahedra that share corners with five TiN3O3 octahedra, a cornercorner with one TiN3O3 pentagonal pyramid, edges with five TiN4O2 octahedra, and an edgeedge with one TiN3O3 pentagonal pyramid. The corner-sharing octahedra tilt angles range from 51–54°. There are a spread of Ti–N bond distances ranging from 2.01–2.08 Å. There are one shorter (2.02 Å) and one longer (2.05 Å) Ti–O bond lengths. In the eleventh Ti4+ site, Ti4+ is bonded to four N3- and two O2- atoms to form a mixture of distorted edge and corner-sharing TiN4O2 octahedra. The corner-sharing octahedra tilt angles range from 51–57°. There are a spread of Ti–N bond distances ranging from 2.00–2.08 Å. Both Ti–O bond lengths are 2.05 Å. In the twelfth Ti4+ site, Ti4+ is bonded to five N3- and one O2- atom to form distorted TiN5O octahedra that share corners with six TiN3O3 octahedra, edges with four TiN4O2 octahedra, and edges with two TiN3O3 pentagonal pyramids. The corner-sharing octahedra tilt angles range from 50–58°. There are a spread of Ti–N bond distances ranging from 1.99–2.10 Å. The Ti–O bond length is 2.16 Å. In the thirteenth Ti4+ site, Ti4+ is bonded to five N3- and one O2- atom to form a mixture of distorted edge and corner-sharing TiN5O octahedra. The corner-sharing octahedra tilt angles range from 51–54°. There are a spread of Ti–N bond distances ranging from 1.99–2.09 Å. The Ti–O bond length is 2.11 Å. In the fourteenth Ti4+ site, Ti4+ is bonded to four N3- and two O2- atoms to form distorted TiN4O2 octahedra that share corners with six TiN3O3 octahedra, edges with four TiN5O octahedra, and edges with two TiN3O3 pentagonal pyramids. The corner-sharing octahedra tilt angles range from 50–54°. There are a spread of Ti–N bond distances ranging from 1.98–2.07 Å. There are one shorter (2.10 Å) and one longer (2.15 Å) Ti–O bond lengths. In the fifteenth Ti4+ site, Ti4+ is bonded to five N3- and one O2- atom to form distorted TiN5O octahedra that share corners with four TiN5O octahedra, corners with two TiN3O3 pentagonal pyramids, and edges with six TiN3O3 octahedra. The corner-sharing octahedra tilt angles range from 52–54°. There are a spread of Ti–N bond distances ranging from 2.02–2.09 Å. The Ti–O bond length is 2.09 Å. In the sixteenth Ti4+ site, Ti4+ is bonded to five N3- and one O2- atom to form distorted TiN5O octahedra that share corners with six TiN3O3 octahedra and edges with six TiN4O2 octahedra. The corner-sharing octahedra tilt angles range from 51–53°. There are a spread of Ti–N bond distances ranging from 2.02–2.09 Å. The Ti–O bond length is 2.08 Å. There are sixteen inequivalent N3- sites. In the first N3- site, N3- is bonded to four Ti4+ atoms to form distorted NTi4 trigonal pyramids that share a cornercorner with one OTi4 trigonal pyramid, corners with nine NTi4 trigonal pyramids, an edgeedge with one NTi4 trigonal pyramid, and edges with two OTi4 trigonal pyramids. In the second N3- site, N3- is bonded to four Ti4+ atoms to form distorted NTi4 trigonal pyramids that share corners with four OTi4 trigonal pyramids, corners with eight NTi4 trigonal pyramids, an edgeedge with one NTi4 trigonal pyramid, and an edgeedge with one OTi4 trigonal pyramid. In the third N3- site, N3- is bonded to four Ti4+ atoms to form distorted NTi4 trigonal pyramids that share corners with two OTi4 trigonal pyramids, corners with seven NTi4 trigonal pyramids, edges with two NTi4 trigonal pyramids, and edges with two OTi4 trigonal pyramids. In the fourth N3- site, N3- is bonded to four Ti4+ atoms to form NTi4 trigonal pyramids that share corners with two OTi4 trigonal pyramids, corners with eight NTi4 trigonal pyramids, edges with two NTi4 trigonal pyramids, and edges with two OTi4 trigonal pyramids. In the fifth N3- site, N3- is bonded to four Ti4+ atoms to form distorted NTi4 trigonal pyramids that share corners with two OTi4 trigonal pyramids, corners with eight NTi4 trigonal pyramids, an edgeedge with one NTi4 trigonal pyramid, and edges with three OTi4 trigonal pyramids. In the sixth N3- site, N3- is bonded to four Ti4+ atoms to form NTi4 trigonal pyramids that share corners with three OTi4 trigonal pyramids, corners with seven NTi4 trigonal pyramids, an edgeedge with one OTi4 trigonal pyramid, and edges with three NTi4 trigonal pyramids. In the seventh N3- site, N3- is bonded to four Ti4+ atoms to form distorted NTi4 trigonal pyramids that share corners with four OTi4 trigonal pyramids, corners with eight NTi4 trigonal pyramids, and edges with three NTi4 trigonal pyramids. In the eighth N3- site, N3- is bonded to four Ti4+ atoms to form distorted NTi4 trigonal pyramids that share corners with three OTi4 trigonal pyramids, corners with eight NTi4 trigonal pyramids, an edgeedge with one OTi4 trigonal pyramid, and edges with two NTi4 trigonal pyramids. In the ninth N3- site, N3- is bonded to four Ti4+ atoms to form distorted NTi4 trigonal pyramids that share corners with four OTi4 trigonal pyramids, corners with seven NTi4 trigonal pyramids, an edgeedge with one OTi4 trigonal pyramid, and edges with two NTi4 trigonal pyramids. In the tenth N3- site, N3- is bonded to four Ti4+ atoms to form distorted NTi4 trigonal pyramids that share corners with five OTi4 trigonal pyramids, corners with six NTi4 trigonal pyramids, and edges with three NTi4 trigonal pyramids. In the eleventh N3- site, N3- is bonded to four Ti4+ atoms to form distorted NTi4 trigonal pyramids that share corners with three OTi4 trigonal pyramids, corners with eight NTi4 trigonal pyramids, an edgeedge with one OTi4 trigonal pyramid, and edges with three NTi4 trigonal pyramids. In the twelfth N3- site, N3- is bonded in a distorted rectangular see-saw-like geometry to four Ti4+ atoms. In the thirteenth N3- site, N3- is bonded to four Ti4+ atoms to form distorted NTi4 trigonal pyramids that share corners with three OTi4 trigonal pyramids, corners with eight NTi4 trigonal pyramids, an edgeedge with one NTi4 trigonal pyramid, and edges with two OTi4 trigonal pyramids. In the fourteenth N3- site, N3- is bonded to four Ti4+ atoms to form distorted NTi4 trigonal pyramids that share corners with four OTi4 trigonal pyramids, corners with seven NTi4 trigonal pyramids, an edgeedge with one OTi4 trigonal pyramid, and edges with three NTi4 trigonal pyramids. In the fifteenth N3- site, N3- is bonded to four Ti4+ atoms to form distorted NTi4 trigonal pyramids that share corners with three OTi4 trigonal pyramids, corners with seven NTi4 trigonal pyramids, an edgeedge with one OTi4 trigonal pyramid, and edges with three NTi4 trigonal pyramids. In the sixteenth N3- site, N3- is bonded to four Ti4+ atoms to form distorted NTi4 trigonal pyramids that share corners with two OTi4 trigonal pyramids, corners with eight NTi4 trigonal pyramids, an edgeedge with one OTi4 trigonal pyramid, and edges with two NTi4 trigonal pyramids. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to four Ti4+ atoms. In the second O2- site, O2- is bonded to four Ti4+ atoms to form OTi4 trigonal pyramids that share corners with five OTi4 trigonal pyramids, corners with six NTi4 trigonal pyramids, and edges with three NTi4 trigonal pyramids. In the third O2- site, O2- is bonded in a rectangular see-saw-like geometry to four Ti4+ atoms. In the fourth O2- site, O2- is bonded to four Ti4+ atoms to form distorted OTi4 trigonal pyramids that share corners with two OTi4 trigonal pyramids, corners with seven NTi4 trigonal pyramids, and edges with four NTi4 trigonal pyramids. In the fifth O2- site, O2- is bonded to four Ti4+ atoms to form distorted OTi4 trigonal pyramids that share corners with three OTi4 trigonal pyramids, corners with seven NTi4 trigonal pyramids, an edgeedge with one OTi4 trigonal pyramid, and edges with two NTi4 trigonal pyramids. In the sixth O2- site, O2- is bonded to four Ti4+ atoms to form distorted OTi4 trigonal

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ti2N2O by Materials Project

Ti2N2O is Ilmenite-like structured and crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are sixteen inequivalent Ti4+ sites. In the first Ti4+ site, Ti4+ is bonded to four N3- and two O2- atoms to form TiN4O2 octahedra that share corners with six TiN4O2 octahedra and edges with six TiN3O3 octahedra. The corner-sharing octahedra tilt angles range from 50–55°. There are a spread of Ti–N bond distances ranging from 1.94–2.06 Å. There are one shorter (2.15 Å) and one longer (2.16 Å) Ti–O bond lengths. In the second Ti4+ site, Ti4+ is bonded to three N3- and three O2- atoms to form a mixture of distorted edge and corner-sharing TiN3O3 octahedra. The corner-sharing octahedra tilt angles range from 50–52°. There are a spread of Ti–N bond distances ranging from 1.93–2.09 Å. There are a spread of Ti–O bond distances ranging from 2.01–2.16 Å. In the third Ti4+ site, Ti4+ is bonded to four N3- and two O2- atoms to form distorted TiN4O2 octahedra that share corners with six TiN4O2 octahedra and edges with six TiN3O3 octahedra. The corner-sharing octahedra tilt angles range from 49–55°. There are a spread of Ti–N bond distances ranging from 2.03–2.08 Å. There are one shorter (2.01 Å) and one longer (2.06 Å) Ti–O bond lengths. In the fourth Ti4+ site, Ti4+ is bonded to four N3- and two O2- atoms to form distorted TiN4O2 octahedra that share corners with six TiN3O3 octahedra and edges with six TiN4O2 octahedra. The corner-sharing octahedra tilt angles range from 50–56°. There are a spread of Ti–N bond distances ranging from 2.02–2.09 Å. There are one shorter (2.02 Å) and one longer (2.07 Å) Ti–O bond lengths. In the fifth Ti4+ site, Ti4+ is bonded to four N3- and two O2- atoms to form a mixture of distorted edge and corner-sharing TiN4O2 octahedra. The corner-sharing octahedra tilt angles range from 48–58°. There are a spread of Ti–N bond distances ranging from 1.97–2.08 Å. There are one shorter (2.10 Å) and one longer (2.18 Å) Ti–O bond lengths. In the sixth Ti4+ site, Ti4+ is bonded to three N3- and three O2- atoms to form a mixture of distorted edge and corner-sharing TiN3O3 octahedra. The corner-sharing octahedra tilt angles range from 50–57°. There are a spread of Ti–N bond distances ranging from 1.92–2.05 Å. There are a spread of Ti–O bond distances ranging from 2.01–2.20 Å. In the seventh Ti4+ site, Ti4+ is bonded to four N3- and two O2- atoms to form TiN4O2 octahedra that share corners with six TiN4O2 octahedra and edges with six TiN3O3 octahedra. The corner-sharing octahedra tilt angles range from 52–55°. There are a spread of Ti–N bond distances ranging from 1.96–2.14 Å. There are one shorter (2.12 Å) and one longer (2.13 Å) Ti–O bond lengths. In the eighth Ti4+ site, Ti4+ is bonded to three N3- and three O2- atoms to form TiN3O3 octahedra that share corners with six TiN3O3 octahedra and edges with six TiN4O2 octahedra. The corner-sharing octahedra tilt angles range from 46–55°. There is two shorter (1.95 Å) and one longer (2.02 Å) Ti–N bond length. There are one shorter (2.05 Å) and two longer (2.12 Å) Ti–O bond lengths. In the ninth Ti4+ site, Ti4+ is bonded to five N3- and one O2- atom to form a mixture of distorted edge and corner-sharing TiN5O octahedra. The corner-sharing octahedra tilt angles range from 50–57°. There are a spread of Ti–N bond distances ranging from 1.99–2.08 Å. The Ti–O bond length is 2.11 Å. In the tenth Ti4+ site, Ti4+ is bonded to five N3- and one O2- atom to form TiN5O octahedra that share corners with six TiN3O3 octahedra and edges with six TiN4O2 octahedra. The corner-sharing octahedra tilt angles range from 49–58°. There are a spread of Ti–N bond distances ranging from 1.96–2.12 Å. The Ti–O bond length is 2.18 Å. In the eleventh Ti4+ site, Ti4+ is bonded to three N3- and three O2- atoms to form a mixture of distorted edge and corner-sharing TiN3O3 octahedra. The corner-sharing octahedra tilt angles range from 48–55°. There are a spread of Ti–N bond distances ranging from 1.97–2.11 Å. There are a spread of Ti–O bond distances ranging from 2.02–2.12 Å. In the twelfth Ti4+ site, Ti4+ is bonded to four N3- and two O2- atoms to form distorted TiN4O2 octahedra that share corners with six TiN4O2 octahedra and edges with six TiN3O3 octahedra. The corner-sharing octahedra tilt angles range from 50–55°. There are a spread of Ti–N bond distances ranging from 1.97–2.07 Å. There are one shorter (2.08 Å) and one longer (2.12 Å) Ti–O bond lengths. In the thirteenth Ti4+ site, Ti4+ is bonded to five N3- and one O2- atom to form distorted TiN5O octahedra that share corners with six TiN3O3 octahedra and edges with six TiN4O2 octahedra. The corner-sharing octahedra tilt angles range from 50–53°. There are a spread of Ti–N bond distances ranging from 1.98–2.14 Å. The Ti–O bond length is 2.13 Å. In the fourteenth Ti4+ site, Ti4+ is bonded to four N3- and two O2- atoms to form distorted TiN4O2 octahedra that share corners with six TiN4O2 octahedra and edges with six TiN3O3 octahedra. The corner-sharing octahedra tilt angles range from 46–53°. There are a spread of Ti–N bond distances ranging from 2.00–2.09 Å. Both Ti–O bond lengths are 2.03 Å. In the fifteenth Ti4+ site, Ti4+ is bonded to four N3- and two O2- atoms to form distorted TiN4O2 octahedra that share corners with six TiN3O3 octahedra and edges with six TiN4O2 octahedra. The corner-sharing octahedra tilt angles range from 49–52°. There are two shorter (2.04 Å) and two longer (2.05 Å) Ti–N bond lengths. There are one shorter (2.04 Å) and one longer (2.05 Å) Ti–O bond lengths. In the sixteenth Ti4+ site, Ti4+ is bonded to five N3- and one O2- atom to form a mixture of distorted edge and corner-sharing TiN5O octahedra. The corner-sharing octahedra tilt angles range from 49–56°. There are a spread of Ti–N bond distances ranging from 1.96–2.09 Å. The Ti–O bond length is 2.21 Å. There are sixteen inequivalent N3- sites. In the first N3- site, N3- is bonded in a distorted rectangular see-saw-like geometry to four Ti4+ atoms. In the second N3- site, N3- is bonded to four Ti4+ atoms to form distorted NTi4 trigonal pyramids that share corners with three OTi4 trigonal pyramids, corners with five NTi4 trigonal pyramids, edges with two NTi4 trigonal pyramids, and edges with two OTi4 trigonal pyramids. In the third N3- site, N3- is bonded to four Ti4+ atoms to form distorted NTi4 trigonal pyramids that share corners with two OTi4 trigonal pyramids, corners with nine NTi4 trigonal pyramids, and edges with three OTi4 trigonal pyramids. In the fourth N3- site, N3- is bonded in a distorted rectangular see-saw-like geometry to four Ti4+ atoms. In the fifth N3- site, N3- is bonded to four Ti4+ atoms to form distorted NTi4 trigonal pyramids that share corners with two OTi4 trigonal pyramids, corners with seven NTi4 trigonal pyramids, an edgeedge with one OTi4 trigonal pyramid, and edges with two NTi4 trigonal pyramids. In the sixth N3- site, N3- is bonded to four Ti4+ atoms to form distorted NTi4 trigonal pyramids that share corners with three OTi4 trigonal pyramids, corners with five NTi4 trigonal pyramids, an edgeedge with one OTi4 trigonal pyramid, and edges with two NTi4 trigonal pyramids. In the seventh N3- site, N3- is bonded to four Ti4+ atoms to form distorted NTi4 trigonal pyramids that share corners with three OTi4 trigonal pyramids, corners with seven NTi4 trigonal pyramids, an edgeedge with one OTi4 trigonal pyramid, and edges with three NTi4 trigonal pyramids. In the eighth N3- site, N3- is bonded to four Ti4+ atoms to form distorted NTi4 trigonal pyramids that share corners with three OTi4 trigonal pyramids, corners with seven NTi4 trigonal pyramids, an edgeedge with one NTi4 trigonal pyramid, and edges with two OTi4 trigonal pyramids. In the ninth N3- site, N3- is bonded to four Ti4+ atoms to form distorted NTi4 trigonal pyramids that share corners with three OTi4 trigonal pyramids, corners with seven NTi4 trigonal pyramids, and edges with three NTi4 trigonal pyramids. In the tenth N3- site, N3- is bonded to four Ti4+ atoms to form NTi4 trigonal pyramids that share corners with three OTi4 trigonal pyramids, corners with five NTi4 trigonal pyramids, and edges with four NTi4 trigonal pyramids. In the eleventh N3- site, N3- is bonded to four Ti4+ atoms to form distorted NTi4 trigonal pyramids that share corners with two OTi4 trigonal pyramids, corners with seven NTi4 trigonal pyramids, an edgeedge with one NTi4 trigonal pyramid, and an edgeedge with one OTi4 trigonal pyramid. In the twelfth N3- site, N3- is bonded to four Ti4+ atoms to form distorted NTi4 trigonal pyramids that share corners with two OTi4 trigonal pyramids, corners with seven NTi4 trigonal pyramids, an edgeedge with one NTi4 trigonal pyramid, and edges with two OTi4 trigonal pyramids. In the thirteenth N3- site, N3- is bonded to four Ti4+ atoms to form distorted NTi4 trigonal pyramids that share corners with two OTi4 trigonal pyramids, corners with seven NTi4 trigonal pyramids, and edges with two NTi4 trigonal pyramids. In the fourteenth N3- site, N3- is bonded to four Ti4+ atoms to form distorted NTi4 trigonal pyramids that share corners with two OTi4 trigonal pyramids, corners with nine NTi4 trigonal pyramids, an edgeedge with one OTi4 trigonal pyramid, and edges with two NTi4 trigonal pyramids. In the fifteenth N3- site, N3- is bonded to four Ti4+ atoms to form distorted NTi4 trigonal pyramids that share corners with three OTi4 trigonal pyramids, corners with seven NTi4 trigonal pyramids, and edges with two NTi4 trigonal pyramids. In the sixteenth N3- site, N3- is bonded to four Ti4+ atoms to form NTi4 trigonal pyramids that share corners with two OTi4 trigonal pyramids, corners with seven NTi4 trigonal pyramids, an edgeedge with one OTi4 trigonal pyramid, and edges with three NTi4 trigonal pyramids. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded to four Ti4+ atoms to form distorted OTi4 trigonal pyramids that share corners with two OTi4 trigonal pyramids, corners with seven NTi4 trigonal pyramids, and edges with three NTi4 trigonal pyramids. In the second O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to four Ti4+ atoms. In the third O2- site, O2- is bonded to four Ti4+ atoms to form distorted OTi4 trigonal pyramids that share corners with three OTi4 trigonal pyramids, corners with seven NTi4 trigonal pyramids, and edges with three NTi4 trigonal pyramids. In the fourth O2- site, O2- is bonded to four Ti4+ atoms to form distorted OTi4 trigonal pyramids that share corners with three OTi4 trigonal pyramids, corners with seven NTi4 trigonal pyramids, and edges with four NTi4 trigonal pyramids. In the fifth O2- site, O2- is bonded to four Ti4+ atoms to form distorted OTi4 trigonal pyramids that share corners with two OTi4 trigonal pyramids, corners with seven NTi4 trigonal pyramids, an edgeedge with one OTi4 trigonal pyramid, and edges with two NTi4 trigonal pyramids. In the sixth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to four Ti4+ atoms. In the seventh O2- site, O2- is bonded to four Ti4+ atoms to form distorted OTi4 trigonal pyramids that share corners with two OTi4 trigonal pyramids, corners with seven NTi4 trigonal pyramids, an edgeedge with one OTi4 trigonal pyramid, and edges with three NTi4 trigonal pyramids. In the eighth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to four Ti4+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ti2N2O by Materials Project

Ti2N2O is Ilmenite-like structured and crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are sixteen inequivalent Ti4+ sites. In the first Ti4+ site, Ti4+ is bonded to four N3- and two O2- atoms to form a mixture of distorted corner and edge-sharing TiN4O2 octahedra. The corner-sharing octahedra tilt angles range from 49–52°. There are a spread of Ti–N bond distances ranging from 2.02–2.07 Å. Both Ti–O bond lengths are 2.03 Å. In the second Ti4+ site, Ti4+ is bonded to four N3- and two O2- atoms to form a mixture of corner and edge-sharing TiN4O2 octahedra. The corner-sharing octahedra tilt angles range from 52–58°. There are a spread of Ti–N bond distances ranging from 1.96–2.08 Å. There are one shorter (2.09 Å) and one longer (2.15 Å) Ti–O bond lengths. In the third Ti4+ site, Ti4+ is bonded to three N3- and three O2- atoms to form distorted TiN3O3 octahedra that share corners with five TiN4O2 octahedra, a cornercorner with one TiN5O pentagonal pyramid, edges with five TiN4O2 octahedra, and an edgeedge with one TiN4O2 pentagonal pyramid. The corner-sharing octahedra tilt angles range from 50–55°. There are a spread of Ti–N bond distances ranging from 1.96–2.06 Å. There are a spread of Ti–O bond distances ranging from 2.01–2.13 Å. In the fourth Ti4+ site, Ti4+ is bonded to four N3- and two O2- atoms to form distorted TiN4O2 octahedra that share corners with five TiN4O2 octahedra, a cornercorner with one TiN5O pentagonal pyramid, edges with five TiN4O2 octahedra, and an edgeedge with one TiN4O2 pentagonal pyramid. The corner-sharing octahedra tilt angles range from 51–54°. There are a spread of Ti–N bond distances ranging from 2.02–2.08 Å. There are one shorter (1.99 Å) and one longer (2.10 Å) Ti–O bond lengths. In the fifth Ti4+ site, Ti4+ is bonded to four N3- and two O2- atoms to form distorted TiN4O2 octahedra that share corners with five TiN3O3 octahedra, a cornercorner with one TiN5O pentagonal pyramid, edges with five TiN4O2 octahedra, and an edgeedge with one TiN4O2 pentagonal pyramid. The corner-sharing octahedra tilt angles range from 50–55°. There are a spread of Ti–N bond distances ranging from 1.98–2.09 Å. Both Ti–O bond lengths are 2.10 Å. In the sixth Ti4+ site, Ti4+ is bonded to four N3- and two O2- atoms to form distorted TiN4O2 octahedra that share corners with five TiN4O2 octahedra, a cornercorner with one TiN4O2 pentagonal pyramid, edges with five TiN3O3 octahedra, and an edgeedge with one TiN5O pentagonal pyramid. The corner-sharing octahedra tilt angles range from 50–54°. There are a spread of Ti–N bond distances ranging from 1.97–2.08 Å. There are one shorter (2.12 Å) and one longer (2.14 Å) Ti–O bond lengths. In the seventh Ti4+ site, Ti4+ is bonded to four N3- and two O2- atoms to form TiN4O2 octahedra that share corners with four TiN3O3 octahedra, corners with two TiN4O2 pentagonal pyramids, and edges with six TiN4O2 octahedra. The corner-sharing octahedra tilt angles range from 51–57°. There are a spread of Ti–N bond distances ranging from 1.96–2.13 Å. There are one shorter (2.12 Å) and one longer (2.13 Å) Ti–O bond lengths. In the eighth Ti4+ site, Ti4+ is bonded to four N3- and two O2- atoms to form TiN4O2 octahedra that share corners with six TiN4O2 octahedra, edges with four TiN3O3 octahedra, and edges with two TiN4O2 pentagonal pyramids. The corner-sharing octahedra tilt angles range from 50–53°. There are a spread of Ti–N bond distances ranging from 1.93–2.07 Å. Both Ti–O bond lengths are 2.16 Å. In the ninth Ti4+ site, Ti4+ is bonded to four N3- and two O2- atoms to form distorted TiN4O2 pentagonal pyramids that share corners with six TiN4O2 octahedra and edges with six TiN3O3 octahedra. The corner-sharing octahedra tilt angles range from 49–54°. There are a spread of Ti–N bond distances ranging from 1.96–2.08 Å. There are one shorter (2.08 Å) and one longer (2.14 Å) Ti–O bond lengths. In the tenth Ti4+ site, Ti4+ is bonded to four N3- and two O2- atoms to form a mixture of corner and edge-sharing TiN4O2 octahedra. The corner-sharing octahedra tilt angles range from 49–55°. There are a spread of Ti–N bond distances ranging from 2.01–2.07 Å. There are one shorter (2.00 Å) and one longer (2.06 Å) Ti–O bond lengths. In the eleventh Ti4+ site, Ti4+ is bonded to five N3- and one O2- atom to form a mixture of distorted corner and edge-sharing TiN5O pentagonal pyramids. The corner-sharing octahedra tilt angles range from 51–54°. There are a spread of Ti–N bond distances ranging from 2.01–2.13 Å. The Ti–O bond length is 2.09 Å. In the twelfth Ti4+ site, Ti4+ is bonded to five N3- and one O2- atom to form distorted TiN5O octahedra that share corners with five TiN4O2 octahedra, a cornercorner with one TiN5O pentagonal pyramid, edges with five TiN4O2 octahedra, and an edgeedge with one TiN4O2 pentagonal pyramid. The corner-sharing octahedra tilt angles range from 49–58°. There are a spread of Ti–N bond distances ranging from 1.97–2.11 Å. The Ti–O bond length is 2.15 Å. In the thirteenth Ti4+ site, Ti4+ is bonded to three N3- and three O2- atoms to form distorted TiN3O3 octahedra that share corners with five TiN4O2 octahedra, a cornercorner with one TiN4O2 pentagonal pyramid, edges with five TiN4O2 octahedra, and an edgeedge with one TiN5O pentagonal pyramid. The corner-sharing octahedra tilt angles range from 49–57°. There are a spread of Ti–N bond distances ranging from 1.97–2.12 Å. There are a spread of Ti–O bond distances ranging from 2.03–2.08 Å. In the fourteenth Ti4+ site, Ti4+ is bonded to four N3- and two O2- atoms to form distorted TiN4O2 octahedra that share corners with five TiN4O2 octahedra, a cornercorner with one TiN4O2 pentagonal pyramid, edges with five TiN4O2 octahedra, and an edgeedge with one TiN5O pentagonal pyramid. The corner-sharing octahedra tilt angles range from 49–57°. There are a spread of Ti–N bond distances ranging from 1.98–2.10 Å. There are one shorter (2.12 Å) and one longer (2.18 Å) Ti–O bond lengths. In the fifteenth Ti4+ site, Ti4+ is bonded to five N3- and one O2- atom to form distorted TiN5O octahedra that share corners with five TiN4O2 octahedra, a cornercorner with one TiN4O2 pentagonal pyramid, edges with five TiN4O2 octahedra, and an edgeedge with one TiN5O pentagonal pyramid. The corner-sharing octahedra tilt angles range from 50–55°. There are a spread of Ti–N bond distances ranging from 2.03–2.08 Å. The Ti–O bond length is 2.10 Å. In the sixteenth Ti4+ site, Ti4+ is bonded to three N3- and three O2- atoms to form distorted TiN3O3 octahedra that share corners with six TiN3O3 octahedra and edges with six TiN4O2 octahedra. The corner-sharing octahedra tilt angles range from 49–53°. There are a spread of Ti–N bond distances ranging from 2.00–2.08 Å. There are a spread of Ti–O bond distances ranging from 1.98–2.08 Å. There are sixteen inequivalent N3- sites. In the first N3- site, N3- is bonded to four Ti4+ atoms to form distorted NTi4 trigonal pyramids that share corners with four OTi4 trigonal pyramids, corners with seven NTi4 trigonal pyramids, edges with two NTi4 trigonal pyramids, and edges with two OTi4 trigonal pyramids. In the second N3- site, N3- is bonded in a distorted rectangular see-saw-like geometry to four Ti4+ atoms. In the third N3- site, N3- is bonded to four Ti4+ atoms to form distorted NTi4 trigonal pyramids that share corners with three OTi4 trigonal pyramids, corners with seven NTi4 trigonal pyramids, edges with two NTi4 trigonal pyramids, and edges with two OTi4 trigonal pyramids. In the fourth N3- site, N3- is bonded to four Ti4+ atoms to form distorted NTi4 trigonal pyramids that share corners with three OTi4 trigonal pyramids, corners with seven NTi4 trigonal pyramids, an edgeedge with one NTi4 trigonal pyramid, and edges with three OTi4 trigonal pyramids. In the fifth N3- site, N3- is bonded to four Ti4+ atoms to form distorted NTi4 trigonal pyramids that share corners with three OTi4 trigonal pyramids, corners with seven NTi4 trigonal pyramids, an edgeedge with one NTi4 trigonal pyramid, and edges with three OTi4 trigonal pyramids. In the sixth N3- site, N3- is bonded to four Ti4+ atoms to form distorted NTi4 trigonal pyramids that share corners with four OTi4 trigonal pyramids, corners with seven NTi4 trigonal pyramids, an edgeedge with one OTi4 trigonal pyramid, and edges with three NTi4 trigonal pyramids. In the seventh N3- site, N3- is bonded to four Ti4+ atoms to form distorted NTi4 trigonal pyramids that share corners with five OTi4 trigonal pyramids, corners with seven NTi4 trigonal pyramids, an edgeedge with one OTi4 trigonal pyramid, and edges with two NTi4 trigonal pyramids. In the eighth N3- site, N3- is bonded to four Ti4+ atoms to form distorted NTi4 trigonal pyramids that share corners with five OTi4 trigonal pyramids, corners with seven NTi4 trigonal pyramids, an edgeedge with one NTi4 trigonal pyramid, and edges with two OTi4 trigonal pyramids. In the ninth N3- site, N3- is bonded to four Ti4+ atoms to form distorted NTi4 trigonal pyramids that share corners with four OTi4 trigonal pyramids, corners with seven NTi4 trigonal pyramids, an edgeedge with one OTi4 trigonal pyramid, and edges with three NTi4 trigonal pyramids. In the tenth N3- site, N3- is bonded in a distorted rectangular see-saw-like geometry to four Ti4+ atoms. In the eleventh N3- site, N3- is bonded to four Ti4+ atoms to form NTi4 trigonal pyramids that share corners with five OTi4 trigonal pyramids, corners with seven NTi4 trigonal pyramids, an edgeedge with one OTi4 trigonal pyramid, and edges with three NTi4 trigonal pyramids. In the twelfth N3- site, N3- is bonded to four Ti4+ atoms to form distorted NTi4 trigonal pyramids that share corners with five OTi4 trigonal pyramids, corners with seven NTi4 trigonal pyramids, an edgeedge with one OTi4 trigonal pyramid, and edges with three NTi4 trigonal pyramids. In the thirteenth N3- site, N3- is bonded to four Ti4+ atoms to form NTi4 trigonal pyramids that share corners with four OTi4 trigonal pyramids, corners with seven NTi4 trigonal pyramids, an edgeedge with one NTi4 trigonal pyramid, and edges with two OTi4 trigonal pyramids. In the fourteenth N3- site, N3- is bonded to four Ti4+ atoms to form NTi4 trigonal pyramids that share corners with four OTi4 trigonal pyramids, corners with seven NTi4 trigonal pyramids, an edgeedge with one NTi4 trigonal pyramid, and edges with two OTi4 trigonal pyramids. In the fifteenth N3- site, N3- is bonded to four Ti4+ atoms to form distorted NTi4 trigonal pyramids that share corners with four OTi4 trigonal pyramids, corners with seven NTi4 trigonal pyramids, an edgeedge with one OTi4 trigonal pyramid, and edges with three NTi4 trigonal pyramids. In the sixteenth N3- site, N3- is bonded to four Ti4+ atoms to form NTi4 trigonal pyramids that share corners with three OTi4 trigonal pyramids, corners with seven NTi4 trigonal pyramids, edges with two NTi4 trigonal pyramids, and edges with two OTi4 trigonal pyramids. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded to four Ti4+ atoms to form distorted OTi4 trigonal pyramids that share corners with four OTi4 trigonal pyramids, corners with seven NTi4 trigonal pyramids, and edges with three NTi4 trigonal pyramids. In the second O2- site, O2- is bonded to four Ti4+ atoms to form distorted OTi4 trigonal pyramids that share corners with four OTi4 trigonal pyramids, corners with seven NTi4 trigonal pyramids, an edgeedge with one OTi4 trigonal pyramid, and edges with two NTi4 trigonal pyramids. In the third O2- site, O2- is bonded to four Ti4+ atoms to form distorted OTi4 trigonal pyramids that share corners with four OTi4 trigonal pyramids, corners with seven NTi4 trigonal pyramids, an edgeedge with one OTi4 trigonal pyramid, and edges with three NTi4 trigonal pyramids. In the fourth O2- site, O2- is bonded to four Ti4+ atoms to form distorted OTi4 trigonal pyramids that share corners wi

36 MATERIALS SCIENCE↗