Materials Data on Cs4SiSe4 by Materials Project
Cs4SiSe4 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 Se2- atoms to form distorted CsSe6 octahedra that share corners with three equivalent SiSe4 tetrahedra, edges with three equivalent CsSe6 octahedra, and a faceface with one SiSe4 tetrahedra. There are three shorter (3.73 Å) and three longer (3.81 Å) Cs–Se bond lengths. In the second Cs1+ site, Cs1+ is bonded in a 6-coordinate geometry to six Se2- atoms. There are a spread of Cs–Se bond distances ranging from 3.68–3.83 Å. There are two inequivalent Si4+ sites. In the first Si4+ site, Si4+ is bonded to four equivalent Se2- atoms to form SiSe4 tetrahedra that share corners with four equivalent CsSe6 octahedra. The corner-sharing octahedral tilt angles are 47°. All Si–Se bond lengths are 2.32 Å. In the second Si4+ site, Si4+ is bonded to four equivalent Se2- atoms to form SiSe4 tetrahedra that share faces with four equivalent CsSe6 octahedra. All Si–Se bond lengths are 2.31 Å. There are two inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 1-coordinate geometry to six Cs1+ and one Si4+ atom. In the second Se2- site, Se2- is bonded in a distorted single-bond geometry to six Cs1+ and one Si4+ atom.