DOI: 10.17188/1475834
title: Materials Data on Ca7MgFeCo7O24 by Materials Project

description: Ca7MgFeCo7O24 is (Cubic) Perovskite-derived structured and crystallizes in the trigonal R3m space group. The structure is three-dimensional. there are three inequivalent Ca sites. In the first Ca site, Ca is bonded to twelve O atoms to form CaO12 cuboctahedra that share corners with twelve CaO12 cuboctahedra, faces with two equivalent MgO12 cuboctahedra, faces with four equivalent CaO12 cuboctahedra, a faceface with one FeO6 octahedra, and faces with seven CoO6 octahedra. There are a spread of Ca–O bond distances ranging from 2.66–2.68 Å. In the second Ca site, Ca is bonded to twelve O atoms to form CaO12 cuboctahedra that share corners with four equivalent MgO12 cuboctahedra, corners with eight equivalent CaO12 cuboctahedra, faces with six CaO12 cuboctahedra, a faceface with one FeO6 octahedra, and faces with seven CoO6 octahedra. There are a spread of Ca–O bond distances ranging from 2.67–2.70 Å. In the third Ca site, Ca is bonded to twelve O atoms to form CaO12 cuboctahedra that share corners with twelve equivalent CaO12 cuboctahedra, faces with six equivalent CaO12 cuboctahedra, a faceface with one FeO6 octahedra, and faces with seven CoO6 octahedra. There are a spread of Ca–O bond distances ranging from 2.67–2.69 Å. Mg is bonded to twelve O atoms to form MgO12 cuboctahedra that share corners with twelve equivalent CaO12 cuboctahedra, faces with six equivalent CaO12 cuboctahedra, a faceface with one FeO6 octahedra, and faces with seven CoO6 octahedra. There are a spread of Mg–O bond distances ranging from 2.63–2.66 Å. Fe is bonded to six O atoms to form FeO6 octahedra that share corners with six equivalent CoO6 octahedra, a faceface with one MgO12 cuboctahedra, and faces with seven CaO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–1°. All Fe–O bond lengths are 1.93 Å. There are three inequivalent Co sites. In the first Co site, Co is bonded to six O atoms to form CoO6 octahedra that share corners with six equivalent CoO6 octahedra, a faceface with one MgO12 cuboctahedra, and faces with seven CaO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–1°. All Co–O bond lengths are 1.86 Å. In the second Co site, Co is bonded to six O atoms to form CoO6 octahedra that share corners with two equivalent FeO6 octahedra, corners with four equivalent CoO6 octahedra, a faceface with one MgO12 cuboctahedra, and faces with seven CaO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–1°. There are a spread of Co–O bond distances ranging from 1.85–1.87 Å. In the third Co site, Co is bonded to six O atoms to form CoO6 octahedra that share corners with six CoO6 octahedra, a faceface with one MgO12 cuboctahedra, and faces with seven CaO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–1°. There are a spread of Co–O bond distances ranging from 1.90–1.93 Å. There are six inequivalent O sites. In the first O site, O is bonded in a distorted linear geometry to three Ca, one Mg, one Fe, and one Co atom. In the second O site, O is bonded in a distorted linear geometry to three Ca, one Mg, and two Co atoms. In the third O site, O is bonded in a distorted linear geometry to three Ca, one Mg, and two Co atoms. In the fourth O site, O is bonded to four Ca, one Fe, and one Co atom to form distorted OCa4FeCo octahedra that share corners with twelve OCa4Co2 octahedra, edges with four equivalent OCa4Co2 octahedra, and faces with four OCa4FeCo octahedra. The corner-sharing octahedra tilt angles range from 2–60°. In the fifth O site, O is bonded to four Ca and two Co atoms to form a mixture of distorted edge, face, and corner-sharing OCa4Co2 octahedra. The corner-sharing octahedra tilt angles range from 1–61°. In the sixth O site, O is bonded to four Ca and two Co atoms to form distorted OCa4Co2 octahedra that share corners with twelve OCa4FeCo octahedra, edges with four equivalent OCa4Co2 octahedra, and faces with four OCa4Co2 octahedra. The corner-sharing octahedra tilt angles range from 2–61°.