Materials Data on Ba3Cd(SiO4)2 by Materials Project

Abstract

Ba3Cd(SiO4)2 crystallizes in the trigonal P-3m1 space group. The structure is three-dimensional. there are two inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded in a 1-coordinate geometry to ten O2- atoms. There are a spread of Ba–O bond distances ranging from 2.49–3.15 Å. In the second Ba2+ site, Ba2+ is bonded to twelve O2- atoms to form distorted BaO12 cuboctahedra that share edges with six equivalent BaO12 cuboctahedra, edges with six equivalent SiO4 tetrahedra, and faces with two equivalent CdO6 octahedra. There are six shorter (2.91 Å) and six longer (3.36 Å) Ba–O bond lengths. Cd2+ is bonded to six equivalent O2- atoms to form CdO6 octahedra that share corners with six equivalent SiO4 tetrahedra and faces with two equivalent BaO12 cuboctahedra. All Cd–O bond lengths are 2.32 Å. Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with three equivalent CdO6 octahedra and edges with three equivalent BaO12 cuboctahedra. The corner-sharing octahedral tilt angles are 17°. There is one shorter (1.62 Å) and three longer (1.67 Å) Si–O bond length. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted linear geometry to four Ba2+ and one Si4+ atom. In the second O2- site, O2- is bonded in a 1-coordinate geometry to four Ba2+, one Cd2+, and one Si4+ atom.