DOI: 10.17188/1318500
title: Materials Data on CaMn2O4 by Materials Project

description: CaMn2O4 crystallizes in the monoclinic Cm space group. The structure is three-dimensional. there are two inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Ca–O bond distances ranging from 2.27–2.65 Å. In the second Ca2+ site, Ca2+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Ca–O bond distances ranging from 2.27–2.68 Å. There are four inequivalent Mn3+ sites. In the first Mn3+ site, Mn3+ is bonded to five O2- atoms to form MnO5 square pyramids that share corners with four MnO6 octahedra and edges with two equivalent MnO5 square pyramids. The corner-sharing octahedra tilt angles range from 51–59°. There are a spread of Mn–O bond distances ranging from 1.95–2.13 Å. In the second Mn3+ site, Mn3+ is bonded to six O2- atoms to form distorted MnO6 octahedra that share corners with four MnO5 square pyramids and edges with four MnO6 octahedra. There are a spread of Mn–O bond distances ranging from 1.97–2.26 Å. In the third Mn3+ site, Mn3+ is bonded to six O2- atoms to form distorted MnO6 octahedra that share corners with four MnO5 square pyramids and edges with four MnO6 octahedra. There are a spread of Mn–O bond distances ranging from 1.97–2.26 Å. In the fourth Mn3+ site, Mn3+ is bonded to five O2- atoms to form MnO5 square pyramids that share corners with four MnO6 octahedra and edges with two equivalent MnO5 square pyramids. The corner-sharing octahedra tilt angles range from 51–59°. There are a spread of Mn–O bond distances ranging from 1.95–2.12 Å. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to one Ca2+ and three Mn3+ atoms. In the second O2- site, O2- is bonded to one Ca2+ and three Mn3+ atoms to form distorted OCaMn3 tetrahedra that share corners with two equivalent OCa2Mn3 square pyramids, corners with two equivalent OCaMn3 tetrahedra, and edges with three OCa2Mn3 square pyramids. In the third O2- site, O2- is bonded to one Ca2+ and three Mn3+ atoms to form distorted OCaMn3 tetrahedra that share corners with two equivalent OCa2Mn3 square pyramids, corners with two equivalent OCaMn3 tetrahedra, and edges with three OCa2Mn3 square pyramids. In the fourth O2- site, O2- is bonded in a 4-coordinate geometry to one Ca2+ and three Mn3+ atoms. In the fifth O2- site, O2- is bonded in a rectangular see-saw-like geometry to two equivalent Ca2+ and two equivalent Mn3+ atoms. In the sixth O2- site, O2- is bonded to two equivalent Ca2+ and three Mn3+ atoms to form distorted OCa2Mn3 square pyramids that share corners with two equivalent OCaMn3 tetrahedra, edges with four OCa2Mn3 square pyramids, and edges with three OCaMn3 tetrahedra. In the seventh O2- site, O2- is bonded in a rectangular see-saw-like geometry to two equivalent Ca2+ and two equivalent Mn3+ atoms. In the eighth O2- site, O2- is bonded to two equivalent Ca2+ and three Mn3+ atoms to form distorted OCa2Mn3 square pyramids that share corners with two equivalent OCaMn3 tetrahedra, edges with four OCa2Mn3 square pyramids, and edges with three OCaMn3 tetrahedra.