Materials Data on CaMnO3 by Materials Project

Abstract

CaMnO3 is (Cubic) Perovskite-like structured and crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. there are two inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded to twelve O2- atoms to form CaO12 cuboctahedra that share corners with six equivalent CaO12 cuboctahedra, corners with six equivalent MnO6 octahedra, faces with eight CaO12 cuboctahedra, and faces with six equivalent MnO6 octahedra. The corner-sharing octahedral tilt angles are 14°. There are six shorter (2.70 Å) and six longer (2.83 Å) Ca–O bond lengths. In the second Ca2+ site, Ca2+ is bonded to twelve O2- atoms to form CaO12 cuboctahedra that share corners with twelve equivalent CaO12 cuboctahedra, faces with six equivalent CaO12 cuboctahedra, and faces with eight equivalent MnO6 octahedra. There are six shorter (2.70 Å) and six longer (2.78 Å) Ca–O bond lengths. Mn4+ is bonded to six O2- atoms to form MnO6 octahedra that share corners with three equivalent CaO12 cuboctahedra, corners with three equivalent MnO6 octahedra, faces with seven CaO12 cuboctahedra, and a faceface with one MnO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There is three shorter (1.88 Å) and three longer (1.93 Å) Mn–O bond length. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted linear geometry to four Ca2+ and two equivalent Mn4+ atoms. In the second O2- site, O2- is bonded in a 2-coordinate geometry to four Ca2+ and two equivalent Mn4+ atoms.