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All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on Pr2Se2O by Materials Project

Pr2Se2O crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. there are two inequivalent Pr3+ sites. In the first Pr3+ site, Pr3+ is bonded in a 1-coordinate geometry to six Se2- and one O2- atom. There are a spread of Pr–Se bond distances ranging from 2.96–3.15 Å. The Pr–O bond length is 2.40 Å. In the second Pr3+ site, Pr3+ is bonded in a 7-coordinate geometry to three Se2- and three equivalent O2- atoms. There are a spread of Pr–Se bond distances ranging from 3.02–3.17 Å. There are one shorter (2.41 Å) and two longer (2.44 Å) Pr–O bond lengths. There are two inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 5-coordinate geometry to five Pr3+ atoms. In the second Se2- site, Se2- is bonded in a 4-coordinate geometry to four Pr3+ atoms. O2- is bonded to four Pr3+ atoms to form a mixture of corner and edge-sharing OPr4 tetrahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Pr4Se3O4 by Materials Project

Pr4Se3O4 crystallizes in the orthorhombic Amm2 space group. The structure is three-dimensional. there are three inequivalent Pr+3.50+ sites. In the first Pr+3.50+ site, Pr+3.50+ is bonded in a 4-coordinate geometry to four Se2- and four O2- atoms. There are two shorter (3.19 Å) and two longer (3.35 Å) Pr–Se bond lengths. There are a spread of Pr–O bond distances ranging from 2.38–2.42 Å. In the second Pr+3.50+ site, Pr+3.50+ is bonded in a 4-coordinate geometry to four equivalent Se2- and four O2- atoms. All Pr–Se bond lengths are 3.20 Å. There are two shorter (2.38 Å) and two longer (2.41 Å) Pr–O bond lengths. In the third Pr+3.50+ site, Pr+3.50+ is bonded in a 6-coordinate geometry to two equivalent Se2- and four O2- atoms. Both Pr–Se bond lengths are 3.19 Å. There are two shorter (2.34 Å) and two longer (2.38 Å) Pr–O bond lengths. There are two inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 4-coordinate geometry to four Pr+3.50+ and one Se2- atom. The Se–Se bond length is 2.54 Å. In the second Se2- site, Se2- is bonded in a 6-coordinate geometry to six Pr+3.50+ atoms. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded to four Pr+3.50+ atoms to form a mixture of edge and corner-sharing OPr4 tetrahedra. In the second O2- site, O2- is bonded to four Pr+3.50+ atoms to form a mixture of edge and corner-sharing OPr4 tetrahedra. In the third O2- site, O2- is bonded to four Pr+3.50+ atoms to form a mixture of edge and corner-sharing OPr4 tetrahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Pr2SeO2 by Materials Project

Pr2SeO2 crystallizes in the trigonal P-3m1 space group. The structure is three-dimensional. Pr3+ is bonded in a 4-coordinate geometry to three equivalent Se2- and four equivalent O2- atoms. All Pr–Se bond lengths are 3.11 Å. There are one shorter (2.40 Å) and three longer (2.42 Å) Pr–O bond lengths. Se2- is bonded to six equivalent Pr3+ atoms to form distorted SePr6 octahedra that share corners with twelve equivalent OPr4 tetrahedra, edges with six equivalent SePr6 octahedra, and edges with six equivalent OPr4 tetrahedra. O2- is bonded to four equivalent Pr3+ atoms to form OPr4 tetrahedra that share corners with six equivalent SePr6 octahedra, corners with six equivalent OPr4 tetrahedra, edges with three equivalent SePr6 octahedra, and edges with three equivalent OPr4 tetrahedra. The corner-sharing octahedra tilt angles range from 27–49°.

36 MATERIALS SCIENCE↗