Materials Data on Ca3CdO4 by Materials Project

Abstract

Ca3CdO4 is Caswellsilverite-like structured and crystallizes in the tetragonal P4/mmm space group. The structure is three-dimensional. there are two inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded to six O2- atoms to form CaO6 octahedra that share corners with six equivalent CaO6 octahedra, edges with four equivalent CdO6 octahedra, and edges with eight CaO6 octahedra. The corner-sharing octahedra tilt angles range from 0–2°. There are a spread of Ca–O bond distances ranging from 2.37–2.43 Å. In the second Ca2+ site, Ca2+ is bonded to six O2- atoms to form CaO6 octahedra that share corners with two equivalent CdO6 octahedra, corners with four equivalent CaO6 octahedra, and edges with twelve CaO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are two shorter (2.38 Å) and four longer (2.41 Å) Ca–O bond lengths. Cd2+ is bonded to six O2- atoms to form CdO6 octahedra that share corners with two equivalent CaO6 octahedra, corners with four equivalent CdO6 octahedra, edges with four equivalent CdO6 octahedra, and edges with eight equivalent CaO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are four shorter (2.41 Å) and two longer (2.42 Å) Cd–O bond lengths. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded to five Ca2+ and one Cd2+ atom to form a mixture of edge and corner-sharing OCa5Cd octahedra. The corner-sharing octahedra tilt angles range from 0–2°. In the second O2- site, O2- is bonded to two equivalent Ca2+ and four equivalent Cd2+ atoms to form OCa2Cd4 octahedra that share corners with six OCa2Cd4 octahedra and edges with twelve OCa5Cd octahedra. The corner-sharing octahedral tilt angles are 0°. In the third O2- site, O2- is bonded to six Ca2+ atoms to form OCa6 octahedra that share corners with six OCa2Cd4 octahedra and edges with twelve OCa5Cd octahedra. The corner-sharing octahedral tilt angles are 0°.