Materials Data on Ba3CaTiWO9 by Materials Project

Abstract

Ba3CaTiWO9 crystallizes in the hexagonal P6_3mc space group. The structure is three-dimensional. there are three inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded to twelve O2- atoms to form BaO12 cuboctahedra that share corners with twelve BaO12 cuboctahedra, faces with six BaO12 cuboctahedra, faces with two equivalent CaO6 octahedra, and faces with three equivalent WO6 octahedra. There are a spread of Ba–O bond distances ranging from 2.93–3.04 Å. In the second Ba2+ site, Ba2+ is bonded to twelve O2- atoms to form distorted BaO12 cuboctahedra that share corners with nine BaO12 cuboctahedra, faces with seven BaO12 cuboctahedra, faces with three equivalent CaO6 octahedra, and faces with three equivalent WO6 octahedra. There are a spread of Ba–O bond distances ranging from 2.89–3.35 Å. In the third Ba2+ site, Ba2+ is bonded to twelve O2- atoms to form distorted BaO12 cuboctahedra that share corners with nine BaO12 cuboctahedra, corners with three equivalent WO6 octahedra, faces with seven BaO12 cuboctahedra, a faceface with one WO6 octahedra, and faces with three equivalent CaO6 octahedra. The corner-sharing octahedral tilt angles are 10°. There are a spread of Ba–O bond distances ranging from 2.95–3.38 Å. Ca2+ is bonded to six O2- atoms to form CaO6 octahedra that share corners with three equivalent WO6 octahedra and faces with eight BaO12 cuboctahedra. The corner-sharing octahedral tilt angles are 5°. There are three shorter (2.27 Å) and three longer (2.32 Å) Ca–O bond lengths. Ti4+ is bonded in a 6-coordinate geometry to six O2- atoms. There are three shorter (1.83 Å) and three longer (2.24 Å) Ti–O bond lengths. W6+ is bonded to six O2- atoms to form WO6 octahedra that share corners with three equivalent BaO12 cuboctahedra, corners with three equivalent CaO6 octahedra, and faces with seven BaO12 cuboctahedra. The corner-sharing octahedral tilt angles are 5°. There is three shorter (1.92 Å) and three longer (2.00 Å) W–O bond length. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a 6-coordinate geometry to four Ba2+, one Ti4+, and one W6+ atom. In the second O2- site, O2- is bonded in a distorted linear geometry to four Ba2+, one Ca2+, and one W6+ atom. In the third O2- site, O2- is bonded in a 2-coordinate geometry to four Ba2+, one Ca2+, and one Ti4+ atom.