Materials Data on Mn3Cr3O8 by Materials Project

Abstract

Cr3Mn3O8 is Spinel-like structured and crystallizes in the trigonal R-3m space group. The structure is three-dimensional. Cr+3.33+ is bonded to six O2- atoms to form CrO6 octahedra that share corners with six equivalent MnO4 tetrahedra, edges with two equivalent MnO6 octahedra, and edges with four equivalent CrO6 octahedra. All Cr–O bond lengths are 2.04 Å. There are two 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 MnO6 octahedra and corners with nine equivalent CrO6 octahedra. The corner-sharing octahedra tilt angles range from 58–60°. There are three shorter (2.06 Å) and one longer (2.08 Å) Mn–O bond lengths. In the second Mn2+ site, Mn2+ is bonded to six equivalent O2- atoms to form MnO6 octahedra that share corners with six equivalent MnO4 tetrahedra and edges with six equivalent CrO6 octahedra. All Mn–O bond lengths are 2.08 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded to three equivalent Cr+3.33+ and one Mn2+ atom to form distorted OMnCr3 trigonal pyramids that share corners with twelve OMnCr3 trigonal pyramids and edges with three equivalent OMn2Cr2 trigonal pyramids. In the second O2- site, O2- is bonded to two equivalent Cr+3.33+ and two Mn2+ atoms to form a mixture of distorted edge and corner-sharing OMn2Cr2 trigonal pyramids.