DOE OSTI2020
CuMn2O4 is Spinel-like structured and crystallizes in the monoclinic Cm space group. The structure is three-dimensional. there are fifteen inequivalent Mn3+ sites. In the first Mn3+ site, Mn3+ is bonded to four O2- atoms to form MnO4 tetrahedra that share corners with three CuO6 octahedra and corners with nine MnO6 octahedra. The corner-sharing octahedra tilt angles range from 58–62°. There are one shorter (2.02 Å) and three longer (2.04 Å) Mn–O bond lengths. In the second Mn3+ site, Mn3+ is bonded to four O2- atoms to form MnO4 tetrahedra that share corners with three CuO6 octahedra and corners with nine MnO6 octahedra. The corner-sharing octahedra tilt angles range from 58–62°. There are one shorter (2.01 Å) and three longer (2.03 Å) Mn–O bond lengths. In the third Mn3+ site, Mn3+ is bonded to six O2- atoms to form MnO6 octahedra that share corners with three MnO4 tetrahedra, corners with three CuO4 tetrahedra, edges with two equivalent CuO6 octahedra, and edges with four MnO6 octahedra. There are a spread of Mn–O bond distances ranging from 1.98–2.06 Å. In the fourth Mn3+ site, Mn3+ is bonded to four O2- atoms to form MnO4 tetrahedra that share corners with three CuO6 octahedra and corners with nine MnO6 octahedra. The corner-sharing octahedra tilt angles range from 58–61°. There are one shorter (2.01 Å) and three longer (2.03 Å) Mn–O bond lengths. In the fifth Mn3+ site, Mn3+ is bonded to six O2- atoms to form MnO6 octahedra that share corners with three equivalent MnO4 tetrahedra, corners with three equivalent CuO4 tetrahedra, edges with two CuO6 octahedra, and edges with four MnO6 octahedra. There are a spread of Mn–O bond distances ranging from 1.98–2.10 Å. In the sixth Mn3+ site, Mn3+ is bonded to six O2- atoms to form MnO6 octahedra that share corners with three MnO4 tetrahedra, corners with three CuO4 tetrahedra, edges with two equivalent CuO6 octahedra, and edges with four MnO6 octahedra. There are a spread of Mn–O bond distances ranging from 1.98–2.05 Å. In the seventh Mn3+ site, Mn3+ is bonded to six O2- atoms to form MnO6 octahedra that share corners with three equivalent MnO4 tetrahedra, corners with three equivalent CuO4 tetrahedra, edges with two CuO6 octahedra, and edges with four MnO6 octahedra. There are a spread of Mn–O bond distances ranging from 1.98–2.10 Å. In the eighth Mn3+ site, Mn3+ is bonded to four O2- atoms to form MnO4 tetrahedra that share corners with two equivalent CuO6 octahedra and corners with ten MnO6 octahedra. The corner-sharing octahedra tilt angles range from 57–63°. There are a spread of Mn–O bond distances ranging from 2.00–2.04 Å. In the ninth Mn3+ site, Mn3+ is bonded to six O2- atoms to form MnO6 octahedra that share corners with three MnO4 tetrahedra, corners with three CuO4 tetrahedra, edges with two equivalent CuO6 octahedra, and edges with four MnO6 octahedra. There are a spread of Mn–O bond distances ranging from 1.98–2.05 Å. In the tenth Mn3+ site, Mn3+ is bonded to six O2- atoms to form MnO6 octahedra that share corners with three equivalent MnO4 tetrahedra, corners with three equivalent CuO4 tetrahedra, edges with two CuO6 octahedra, and edges with four MnO6 octahedra. There are a spread of Mn–O bond distances ranging from 1.98–2.10 Å. In the eleventh Mn3+ site, Mn3+ is bonded to six O2- atoms to form MnO6 octahedra that share a cornercorner with one MnO4 tetrahedra, corners with five CuO4 tetrahedra, and edges with six MnO6 octahedra. There are a spread of Mn–O bond distances ranging from 2.01–2.09 Å. In the twelfth Mn3+ site, Mn3+ is bonded to six O2- atoms to form MnO6 octahedra that share corners with three equivalent MnO4 tetrahedra, corners with three equivalent CuO4 tetrahedra, an edgeedge with one CuO6 octahedra, and edges with five MnO6 octahedra. There are a spread of Mn–O bond distances ranging from 1.98–2.12 Å. In the thirteenth Mn3+ site, Mn3+ is bonded to six O2- atoms to form MnO6 octahedra that share a cornercorner with one MnO4 tetrahedra, corners with five CuO4 tetrahedra, and edges with six MnO6 octahedra. There are a spread of Mn–O bond distances ranging from 2.00–2.07 Å. In the fourteenth Mn3+ site, Mn3+ is bonded to six O2- atoms to form MnO6 octahedra that share corners with two equivalent MnO4 tetrahedra, corners with four CuO4 tetrahedra, edges with two equivalent CuO6 octahedra, and edges with four MnO6 octahedra. There are a spread of Mn–O bond distances ranging from 1.99–2.04 Å. In the fifteenth Mn3+ site, Mn3+ is bonded to six O2- atoms to form MnO6 octahedra that share corners with six CuO4 tetrahedra, an edgeedge with one CuO6 octahedra, and edges with five MnO6 octahedra. There are a spread of Mn–O bond distances ranging from 1.98–2.10 Å. There are ten inequivalent Cu2+ sites. In the first Cu2+ site, Cu2+ is bonded to four O2- atoms to form CuO4 tetrahedra that share corners with three CuO6 octahedra and corners with nine MnO6 octahedra. The corner-sharing octahedra tilt angles range from 57–61°. There are a spread of Cu–O bond distances ranging from 1.96–2.03 Å. In the second Cu2+ site, Cu2+ is bonded to four O2- atoms to form CuO4 tetrahedra that share corners with three CuO6 octahedra and corners with nine MnO6 octahedra. The corner-sharing octahedra tilt angles range from 57–62°. There are a spread of Cu–O bond distances ranging from 1.96–2.03 Å. In the third Cu2+ site, Cu2+ is bonded to six O2- atoms to form CuO6 octahedra that share corners with three MnO4 tetrahedra, corners with three CuO4 tetrahedra, and edges with six MnO6 octahedra. There are a spread of Cu–O bond distances ranging from 2.07–2.11 Å. In the fourth Cu2+ site, Cu2+ is bonded to four O2- atoms to form CuO4 tetrahedra that share corners with three CuO6 octahedra and corners with nine MnO6 octahedra. The corner-sharing octahedra tilt angles range from 57–62°. There are a spread of Cu–O bond distances ranging from 1.96–2.03 Å. In the fifth Cu2+ site, Cu2+ is bonded to six O2- atoms to form CuO6 octahedra that share corners with three MnO4 tetrahedra, corners with three CuO4 tetrahedra, and edges with six MnO6 octahedra. There are four shorter (2.07 Å) and two longer (2.11 Å) Cu–O bond lengths. In the sixth Cu2+ site, Cu2+ is bonded to four O2- atoms to form CuO4 tetrahedra that share a cornercorner with one CuO6 octahedra and corners with eleven MnO6 octahedra. The corner-sharing octahedra tilt angles range from 57–62°. There are a spread of Cu–O bond distances ranging from 2.00–2.03 Å. In the seventh Cu2+ site, Cu2+ is bonded to four O2- atoms to form CuO4 tetrahedra that share a cornercorner with one CuO6 octahedra and corners with eleven MnO6 octahedra. The corner-sharing octahedra tilt angles range from 58–62°. There are a spread of Cu–O bond distances ranging from 1.98–2.02 Å. In the eighth Cu2+ site, Cu2+ is bonded to six O2- atoms to form CuO6 octahedra that share corners with three MnO4 tetrahedra, corners with three CuO4 tetrahedra, and edges with six MnO6 octahedra. There are a spread of Cu–O bond distances ranging from 2.08–2.10 Å. In the ninth Cu2+ site, Cu2+ is bonded to four O2- atoms to form CuO4 tetrahedra that share corners with two equivalent CuO6 octahedra and corners with ten MnO6 octahedra. The corner-sharing octahedra tilt angles range from 57–62°. There are a spread of Cu–O bond distances ranging from 1.97–2.01 Å. In the tenth Cu2+ site, Cu2+ is bonded to six O2- atoms to form CuO6 octahedra that share corners with two equivalent MnO4 tetrahedra, corners with four CuO4 tetrahedra, and edges with six MnO6 octahedra. There are four shorter (2.08 Å) and two longer (2.10 Å) Cu–O bond lengths. There are thirty inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to three Mn3+ and one Cu2+ atom. In the second O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to two Mn3+ and two Cu2+ atoms. In the third O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to two equivalent Mn3+ and two Cu2+ atoms. In the fourth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to three Mn3+ and one Cu2+ atom. In the fifth O2- site, O2- is bonded to three Mn3+ and one Cu2+ atom to form a mixture of distorted edge and corner-sharing OMn3Cu trigonal pyramids. In the sixth O2- site, O2- is bonded to three Mn3+ and one Cu2+ atom to form a mixture of distorted edge and corner-sharing OMn3Cu trigonal pyramids. In the seventh O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to two equivalent Mn3+ and two Cu2+ atoms. In the eighth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to two Mn3+ and two Cu2+ atoms. In the ninth O2- site, O2- is bonded to four Mn3+ atoms to form a mixture of distorted edge and corner-sharing OMn4 trigonal pyramids. In the tenth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to three Mn3+ and one Cu2+ atom. In the eleventh O2- site, O2- is bonded to three Mn3+ and one Cu2+ atom to form a mixture of distorted edge and corner-sharing OMn3Cu trigonal pyramids. In the twelfth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to two equivalent Mn3+ and two Cu2+ atoms. In the thirteenth O2- site, O2- is bonded to three Mn3+ and one Cu2+ atom to form a mixture of distorted edge and corner-sharing OMn3Cu trigonal pyramids. In the fourteenth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to two Mn3+ and two Cu2+ atoms. In the fifteenth O2- site, O2- is bonded to four Mn3+ atoms to form a mixture of distorted edge and corner-sharing OMn4 trigonal pyramids. In the sixteenth O2- site, O2- is bonded in a rectangular see-saw-like geometry to three Mn3+ and one Cu2+ atom. In the seventeenth O2- site, O2- is bonded to three Mn3+ and one Cu2+ atom to form a mixture of distorted edge and corner-sharing OMn3Cu trigonal pyramids. In the eighteenth O2- site, O2- is bonded to three Mn3+ and one Cu2+ atom to form a mixture of distorted edge and corner-sharing OMn3Cu trigonal pyramids. In the nineteenth O2- site, O2- is bonded to three Mn3+ and one Cu2+ atom to form a mixture of distorted edge and corner-sharing OMn3Cu trigonal pyramids. In the twentieth O2- site, O2- is bonded to three Mn3+ and one Cu2+ atom to form a mixture of distorted edge and corner-sharing OMn3Cu trigonal pyramids. In the twenty-first O2- site, O2- is bonded to four Mn3+ atoms to form a mixture of distorted edge and corner-sharing OMn4 trigonal pyramids. In the twenty-second O2- site, O2- is bonded in a rectangular see-saw-like geometry to three Mn3+ and one Cu2+ atom. In the twenty-third O2- site, O2- is bonded to three Mn3+ and one Cu2+ atom to form a mixture of distorted edge and corner-sharing OMn3Cu trigonal pyramids. In the twenty-fourth O2- site, O2- is bonded to four Mn3+ atoms to form a mixture of distorted edge and corner-sharing OMn4 trigonal pyramids. In the twenty-fifth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to two Mn3+ and two Cu2+ atoms. In the twenty-sixth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to two equivalent Mn3+ and two Cu2+ atoms. In the twenty-seventh O2- site, O2- is bonded to three Mn3+ and one Cu2+ atom to form a mixture of distorted edge and corner-sharing OMn3Cu trigonal pyramids. In the twenty-eighth O2- site, O2- is bonded to three Mn3+ and one Cu2+ atom to form a mixture of distorted edge and corner-sharing OMn3Cu trigonal pyramids. In the twenty-ninth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to two equivalent Mn3+ and two Cu2+ atoms. In the thirtieth O2- site, O2- is bonded to four Mn3+ atoms to form a mixture of distorted edge and corner-sharing OMn4 trigonal pyramids.