Materials Data on Ca(CoO2)2 by Materials Project

Abstract

CaCo2O4 is Spinel structured and crystallizes in the tetragonal I4_1/amd space group. The structure is three-dimensional. Ca2+ is bonded to four equivalent O2- atoms to form CaO4 tetrahedra that share corners with twelve equivalent CoO6 octahedra. The corner-sharing octahedra tilt angles range from 55–64°. All Ca–O bond lengths are 2.20 Å. Co3+ is bonded to six equivalent O2- atoms to form distorted CoO6 octahedra that share corners with six equivalent CaO4 tetrahedra and edges with six equivalent CoO6 octahedra. There are four shorter (1.91 Å) and two longer (2.39 Å) Co–O bond lengths. O2- is bonded in a 4-coordinate geometry to one Ca2+ and three equivalent Co3+ atoms.