Materials Data on Ca2TaWO6 by Materials Project
Ca2TaWO6 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 2.24–2.82 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 2.34–2.77 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 WO6 octahedra. The corner-sharing octahedra tilt angles range from 31–32°. There are four shorter (1.99 Å) and two longer (2.07 Å) Ta–O bond lengths. W3+ is bonded to six O2- atoms to form WO6 octahedra that share corners with two equivalent WO6 octahedra and corners with four equivalent TaO6 octahedra. The corner-sharing octahedra tilt angles range from 32–40°. There are a spread of W–O bond distances ranging from 2.12–2.19 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 W3+ atom. In the second O2- site, O2- is bonded in a 5-coordinate geometry to three Ca2+, one Ta5+, and one W3+ atom. In the third O2- site, O2- is bonded to two Ca2+ and two equivalent Ta5+ atoms to form distorted corner-sharing OCa2Ta2 tetrahedra. In the fourth O2- site, O2- is bonded to two Ca2+ and two equivalent W3+ atoms to form distorted corner-sharing OCa2W2 tetrahedra.