Materials Data on Ca2MnO4 by Materials Project

Abstract

Ca2MnO4 is (La,Ba)CuO4 structured and crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Ca2+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Ca–O bond distances ranging from 2.27–2.67 Å. Mn4+ is bonded to six O2- atoms to form corner-sharing MnO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There is four shorter (1.88 Å) and two longer (1.94 Å) Mn–O bond length. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded to four equivalent Ca2+ and two equivalent Mn4+ atoms to form a mixture of distorted corner, edge, and face-sharing OCa4Mn2 octahedra. The corner-sharing octahedra tilt angles range from 0–55°. In the second O2- site, O2- is bonded to five equivalent Ca2+ and one Mn4+ atom to form distorted OCa5Mn octahedra that share corners with seventeen OCa4Mn2 octahedra, edges with eight equivalent OCa5Mn octahedra, and faces with four equivalent OCa4Mn2 octahedra. The corner-sharing octahedra tilt angles range from 0–55°.