Materials Data on MgCr4FeO8 by Materials Project

Abstract

MgCr4FeO8 is Spinel-derived structured and crystallizes in the cubic F-43m space group. The structure is three-dimensional. Mg2+ is bonded to four equivalent O2- atoms to form MgO4 tetrahedra that share corners with twelve equivalent CrO6 octahedra. The corner-sharing octahedral tilt angles are 58°. All Mg–O bond lengths are 2.01 Å. Cr3+ is bonded to six O2- atoms to form CrO6 octahedra that share corners with three equivalent MgO4 tetrahedra, corners with three equivalent FeO4 tetrahedra, and edges with six equivalent CrO6 octahedra. There are three shorter (2.03 Å) and three longer (2.04 Å) Cr–O bond lengths. Fe2+ is bonded to four equivalent O2- atoms to form FeO4 tetrahedra that share corners with twelve equivalent CrO6 octahedra. The corner-sharing octahedral tilt angles are 59°. All Fe–O bond lengths are 2.02 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded to one Mg2+ and three equivalent Cr3+ atoms to form a mixture of distorted edge and corner-sharing OMgCr3 trigonal pyramids. In the second O2- site, O2- is bonded to three equivalent Cr3+ and one Fe2+ atom to form distorted OCr3Fe trigonal pyramids that share corners with twelve OMgCr3 trigonal pyramids and edges with three equivalent OCr3Fe trigonal pyramids.