Materials Data on MgCrO4 by Materials Project

Abstract

MgCrO4 crystallizes in the orthorhombic Cmcm space group. The structure is three-dimensional. Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with six equivalent CrO4 tetrahedra and edges with two equivalent MgO6 octahedra. There are two shorter (2.09 Å) and four longer (2.14 Å) Mg–O bond lengths. Cr6+ is bonded to four O2- atoms to form CrO4 tetrahedra that share corners with six equivalent MgO6 octahedra. The corner-sharing octahedra tilt angles range from 46–53°. There is two shorter (1.63 Å) and two longer (1.70 Å) Cr–O bond length. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Mg2+ and one Cr6+ atom. In the second O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Mg2+ and one Cr6+ atom.