Materials Data on Cs2Se by Materials Project

Abstract

Cs2Se crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. there are two inequivalent Cs1+ sites. In the first Cs1+ site, Cs1+ is bonded to six equivalent Se2- atoms to form distorted CsSe6 octahedra that share corners with twelve equivalent CsSe6 octahedra, corners with twelve equivalent CsSe5 trigonal bipyramids, edges with six equivalent CsSe6 octahedra, faces with two equivalent CsSe6 octahedra, and faces with six equivalent CsSe5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 51°. All Cs–Se bond lengths are 4.06 Å. In the second Cs1+ site, Cs1+ is bonded to five equivalent Se2- atoms to form distorted CsSe5 trigonal bipyramids that share corners with twelve equivalent CsSe6 octahedra, corners with eight equivalent CsSe5 trigonal bipyramids, edges with six equivalent CsSe5 trigonal bipyramids, and faces with six equivalent CsSe6 octahedra. The corner-sharing octahedra tilt angles range from 30–60°. There are three shorter (3.50 Å) and two longer (4.11 Å) Cs–Se bond lengths. Se2- is bonded in a 3-coordinate geometry to eleven Cs1+ atoms.