Materials Data on Mn5CrO8 by Materials Project
CrMn5O8 is Spinel-like structured and crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. Cr6+ is bonded to six O2- atoms to form CrO6 octahedra that share corners with six equivalent MnO4 tetrahedra and edges with six MnO6 octahedra. There are four shorter (2.04 Å) and two longer (2.06 Å) Cr–O bond lengths. There are three inequivalent Mn2+ sites. In the first Mn2+ site, Mn2+ is bonded to four O2- atoms to form MnO4 tetrahedra that share corners with three equivalent CrO6 octahedra and corners with nine MnO6 octahedra. The corner-sharing octahedra tilt angles range from 53–64°. There are three shorter (2.06 Å) and one longer (2.11 Å) Mn–O bond lengths. In the second Mn2+ site, Mn2+ is bonded to six O2- atoms to form MnO6 octahedra that share corners with six equivalent MnO4 tetrahedra, edges with two equivalent CrO6 octahedra, and edges with four equivalent MnO6 octahedra. There are four shorter (1.97 Å) and two longer (2.31 Å) Mn–O bond lengths. In the third Mn2+ site, Mn2+ is bonded to six O2- atoms to form MnO6 octahedra that share corners with six equivalent MnO4 tetrahedra, edges with two equivalent CrO6 octahedra, and edges with four MnO6 octahedra. There are a spread of Mn–O bond distances ranging from 1.96–2.25 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded to one Cr6+ and three Mn2+ atoms to form a mixture of distorted corner and edge-sharing OMn3Cr tetrahedra. In the second O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to four Mn2+ atoms. In the third O2- site, O2- is bonded to one Cr6+ and three Mn2+ atoms to form a mixture of distorted corner and edge-sharing OMn3Cr trigonal pyramids.