Materials Data on Mg(CoO2)2 by Materials Project

Abstract

MgCo2O4 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. Mg2+ is bonded in a 7-coordinate geometry to eight O2- atoms. There are a spread of Mg–O bond distances ranging from 2.15–2.63 Å. There are two inequivalent Co3+ sites. In the first Co3+ site, Co3+ is bonded to six O2- atoms to form a mixture of edge and corner-sharing CoO6 octahedra. The corner-sharing octahedra tilt angles range from 50–61°. There are a spread of Co–O bond distances ranging from 1.91–1.96 Å. In the second Co3+ site, Co3+ is bonded to six O2- atoms to form a mixture of edge and corner-sharing CoO6 octahedra. The corner-sharing octahedra tilt angles range from 50–61°. There are a spread of Co–O bond distances ranging from 1.88–2.00 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded to two equivalent Mg2+ and three Co3+ atoms to form a mixture of distorted edge and corner-sharing OMg2Co3 trigonal bipyramids. In the second O2- site, O2- is bonded to two equivalent Mg2+ and three equivalent Co3+ atoms to form a mixture of distorted edge and corner-sharing OMg2Co3 trigonal bipyramids. In the third O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Mg2+ and three Co3+ atoms. In the fourth O2- site, O2- is bonded in a 5-coordinate geometry to two equivalent Mg2+ and three equivalent Co3+ atoms.