Materials Data on Mg2Cr3O8 by Materials Project

Abstract

Mg2Cr3O8 is beta indium sulfide-derived structured and crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. Mg2+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Mg–O bond distances ranging from 2.10–2.24 Å. There are two inequivalent Cr4+ sites. In the first Cr4+ site, Cr4+ is bonded to six O2- atoms to form edge-sharing CrO6 octahedra. There is four shorter (1.92 Å) and two longer (1.99 Å) Cr–O bond length. In the second Cr4+ site, Cr4+ is bonded to six O2- atoms to form edge-sharing CrO6 octahedra. There are a spread of Cr–O bond distances ranging from 1.89–2.01 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal planar geometry to one Mg2+ and two equivalent Cr4+ atoms. In the second O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Mg2+ and three Cr4+ atoms. In the third O2- site, O2- is bonded to two equivalent Mg2+ and two Cr4+ atoms to form a mixture of distorted corner and edge-sharing OMg2Cr2 trigonal pyramids.