DOI: 10.17188/1731888
title: Materials Data on Ca2Co2O5 by Materials Project

description: Ca2Co2O5 crystallizes in the orthorhombic Pbcm space group. The structure is three-dimensional. there are two inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Ca–O bond distances ranging from 2.31–2.85 Å. In the second Ca2+ site, Ca2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Ca–O bond distances ranging from 2.32–2.90 Å. There are four inequivalent Co3+ sites. In the first Co3+ site, Co3+ is bonded to four O2- atoms to form CoO4 tetrahedra that share corners with two equivalent CoO6 octahedra and corners with two equivalent CoO4 tetrahedra. The corner-sharing octahedral tilt angles are 34°. There are a spread of Co–O bond distances ranging from 1.81–1.97 Å. In the second Co3+ site, Co3+ is bonded to four O2- atoms to form CoO4 tetrahedra that share corners with two equivalent CoO6 octahedra and corners with two equivalent CoO4 tetrahedra. The corner-sharing octahedral tilt angles are 36°. There are a spread of Co–O bond distances ranging from 1.81–1.96 Å. In the third Co3+ site, Co3+ is bonded to six O2- atoms to form CoO6 octahedra that share corners with four equivalent CoO6 octahedra and corners with two equivalent CoO4 tetrahedra. The corner-sharing octahedra tilt angles range from 9–13°. There are a spread of Co–O bond distances ranging from 1.92–2.13 Å. In the fourth Co3+ site, Co3+ is bonded to six O2- atoms to form CoO6 octahedra that share corners with four equivalent CoO6 octahedra and corners with two equivalent CoO4 tetrahedra. The corner-sharing octahedra tilt angles range from 9–13°. There are a spread of Co–O bond distances ranging from 1.93–2.12 Å. There are six inequivalent O2- sites. In the first O2- site, O2- is bonded to two equivalent Ca2+ and two Co3+ atoms to form distorted OCa2Co2 tetrahedra that share corners with eight OCa4Co2 octahedra and corners with two equivalent OCa2Co2 tetrahedra. The corner-sharing octahedra tilt angles range from 22–78°. In the second O2- site, O2- is bonded to four Ca2+ and two Co3+ atoms to form distorted OCa4Co2 octahedra that share corners with two OCa4Co2 octahedra, corners with four OCa2Co2 tetrahedra, edges with two OCa4Co2 octahedra, and faces with four OCa4Co2 octahedra. The corner-sharing octahedra tilt angles range from 0–2°. In the third O2- site, O2- is bonded to two equivalent Ca2+ and two Co3+ atoms to form distorted OCa2Co2 tetrahedra that share corners with eight OCa4Co2 octahedra and corners with two equivalent OCa2Co2 tetrahedra. The corner-sharing octahedra tilt angles range from 21–79°. In the fourth O2- site, O2- is bonded in a 4-coordinate geometry to three Ca2+ and two Co3+ atoms. In the fifth O2- site, O2- is bonded in a 5-coordinate geometry to three Ca2+ and two Co3+ atoms. In the sixth O2- site, O2- is bonded to four Ca2+ and two Co3+ atoms to form distorted OCa4Co2 octahedra that share corners with two OCa4Co2 octahedra, corners with four OCa2Co2 tetrahedra, edges with two OCa4Co2 octahedra, and faces with four OCa4Co2 octahedra. The corner-sharing octahedra tilt angles range from 0–2°.