Materials Data on Mg3Co2O7 by Materials Project

Abstract

Mg3Co2O7 crystallizes in the orthorhombic Cmc2_1 space group. The structure is three-dimensional. there are two inequivalent Mg2+ sites. In the first Mg2+ site, Mg2+ is bonded in a 4-coordinate geometry to eight O2- atoms. There are a spread of Mg–O bond distances ranging from 2.05–2.64 Å. In the second Mg2+ site, Mg2+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Mg–O bond distances ranging from 2.00–2.30 Å. Co4+ is bonded to six O2- atoms to form corner-sharing CoO6 octahedra. The corner-sharing octahedra tilt angles range from 39–43°. There are a spread of Co–O bond distances ranging from 1.86–1.92 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded to three equivalent Mg2+ and one Co4+ atom to form distorted OMg3Co tetrahedra that share corners with six equivalent OMg3Co tetrahedra and a cornercorner with one OMg2Co2 trigonal pyramid. In the second O2- site, O2- is bonded in a 4-coordinate geometry to three Mg2+ and two equivalent Co4+ atoms. In the third O2- site, O2- is bonded in a 5-coordinate geometry to three Mg2+ and two equivalent Co4+ atoms. In the fourth O2- site, O2- is bonded to two equivalent Mg2+ and two equivalent Co4+ atoms to form distorted OMg2Co2 trigonal pyramids that share corners with two equivalent OMg3Co tetrahedra and corners with two equivalent OMg2Co2 trigonal pyramids.