Materials Data on Ca2TaSbO6 by Materials Project

Ca2TaSbO6 crystallizes in the monoclinic P2_1/m space group. The structure is three-dimensional. there are two inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Ca–O bond distances ranging from 2.27–2.83 Å. In the second Ca2+ site, Ca2+ is bonded in a 4-coordinate geometry to eight O2- atoms. There are a spread of Ca–O bond distances ranging from 2.35–2.84 Å. Ta5+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with two equivalent TaO6 octahedra and corners with four equivalent SbO6 octahedra. The corner-sharing octahedra tilt angles range from 35–38°. There are four shorter (1.99 Å) and two longer (2.10 Å) Ta–O bond lengths. Sb3+ is bonded to six O2- atoms to form SbO6 octahedra that share corners with two equivalent SbO6 octahedra and corners with four equivalent TaO6 octahedra. The corner-sharing octahedra tilt angles range from 36–45°. There are a spread of Sb–O bond distances ranging from 2.17–2.37 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a 5-coordinate geometry to three Ca2+, one Ta5+, and one Sb3+ atom. In the second O2- site, O2- is bonded in a 5-coordinate geometry to three Ca2+, one Ta5+, and one Sb3+ atom. In the third O2- site, O2- is bonded to two Ca2+ and two equivalent Sb3+ atoms to form distorted corner-sharing OCa2Sb2 tetrahedra. In the fourth O2- site, O2- is bonded to two Ca2+ and two equivalent Ta5+ atoms to form distorted corner-sharing OCa2Ta2 tetrahedra.