Materials Data on Cs4SiTe4 by Materials Project
Cs4SiTe4 crystallizes in the cubic P-43n space group. The structure is three-dimensional. there are two inequivalent Cs1+ sites. In the first Cs1+ site, Cs1+ is bonded to six Te2- atoms to form distorted CsTe6 octahedra that share corners with six CsTe6 octahedra, corners with three SiTe4 tetrahedra, edges with twelve CsTe6 octahedra, and a faceface with one SiTe4 tetrahedra. The corner-sharing octahedra tilt angles range from 22–27°. There are a spread of Cs–Te bond distances ranging from 3.90–4.04 Å. In the second Cs1+ site, Cs1+ is bonded to six Te2- atoms to form distorted CsTe6 octahedra that share corners with six equivalent CsTe6 octahedra, corners with three equivalent SiTe4 tetrahedra, edges with twelve CsTe6 octahedra, and a faceface with one SiTe4 tetrahedra. The corner-sharing octahedra tilt angles range from 23–25°. There are three shorter (3.96 Å) and three longer (4.03 Å) Cs–Te bond lengths. There are two inequivalent Si4+ sites. In the first Si4+ site, Si4+ is bonded to four equivalent Te2- atoms to form SiTe4 tetrahedra that share corners with twelve CsTe6 octahedra and faces with four equivalent CsTe6 octahedra. The corner-sharing octahedra tilt angles range from 44–50°. All Si–Te bond lengths are 2.56 Å. In the second Si4+ site, Si4+ is bonded to four equivalent Te2- atoms to form SiTe4 tetrahedra that share corners with twelve equivalent CsTe6 octahedra and faces with four equivalent CsTe6 octahedra. The corner-sharing octahedral tilt angles are 50°. All Si–Te bond lengths are 2.55 Å. There are two inequivalent Te2- sites. In the first Te2- site, Te2- is bonded in a 7-coordinate geometry to six Cs1+ and one Si4+ atom. In the second Te2- site, Te2- is bonded in a 7-coordinate geometry to six Cs1+ and one Si4+ atom.