Materials Data on CaCo5O7 by Materials Project
CaCo5O7 crystallizes in the orthorhombic Cmcm space group. The structure is three-dimensional. Ca2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Ca–O bond distances ranging from 2.34–2.73 Å. There are three inequivalent Co+2.40+ sites. In the first Co+2.40+ site, Co+2.40+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing CoO6 octahedra. The corner-sharing octahedra tilt angles range from 0–3°. There are a spread of Co–O bond distances ranging from 2.01–2.20 Å. In the second Co+2.40+ site, Co+2.40+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing CoO6 octahedra. The corner-sharing octahedra tilt angles range from 0–45°. There are a spread of Co–O bond distances ranging from 1.90–2.13 Å. In the third Co+2.40+ site, Co+2.40+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing CoO6 octahedra. The corner-sharing octahedral tilt angles are 3°. There are two shorter (2.09 Å) and four longer (2.16 Å) Co–O bond lengths. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded to one Ca2+ and five Co+2.40+ atoms to form distorted OCaCo5 octahedra that share corners with four OCaCo5 octahedra, corners with four equivalent OCa2Co3 square pyramids, edges with seven OCo6 octahedra, edges with three equivalent OCa2Co3 square pyramids, and edges with two equivalent OCa2Co2 tetrahedra. The corner-sharing octahedra tilt angles range from 0–52°. In the second O2- site, O2- is bonded to two equivalent Ca2+ and two equivalent Co+2.40+ atoms to form distorted OCa2Co2 tetrahedra that share corners with two equivalent OCo6 octahedra, corners with eight equivalent OCa2Co3 square pyramids, corners with two equivalent OCa2Co2 tetrahedra, edges with four equivalent OCaCo5 octahedra, and edges with two equivalent OCa2Co3 square pyramids. The corner-sharing octahedral tilt angles are 1°. In the third O2- site, O2- is bonded to six Co+2.40+ atoms to form OCo6 octahedra that share corners with four OCo6 octahedra, a cornercorner with one OCa2Co3 square pyramid, a cornercorner with one OCa2Co2 tetrahedra, edges with ten OCaCo5 octahedra, and edges with two equivalent OCa2Co3 square pyramids. The corner-sharing octahedra tilt angles range from 0–2°. In the fourth O2- site, O2- is bonded to two equivalent Ca2+ and three Co+2.40+ atoms to form distorted OCa2Co3 square pyramids that share corners with five OCo6 octahedra, corners with two equivalent OCa2Co3 square pyramids, corners with four equivalent OCa2Co2 tetrahedra, edges with five OCaCo5 octahedra, edges with three equivalent OCa2Co3 square pyramids, and an edgeedge with one OCa2Co2 tetrahedra. The corner-sharing octahedra tilt angles range from 7–42°.