Materials Data on CsBi4Se7 by Materials Project

Abstract

CsBi4Se7 is Orthorhombic Perovskite-like structured and crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. Cs1+ is bonded in a 6-coordinate geometry to six Se2- atoms. There are a spread of Cs–Se bond distances ranging from 3.64–3.92 Å. There are four inequivalent Bi+3.25+ sites. In the first Bi+3.25+ site, Bi+3.25+ is bonded to six Se2- atoms to form a mixture of corner and edge-sharing BiSe6 octahedra. The corner-sharing octahedra tilt angles range from 5–6°. There are a spread of Bi–Se bond distances ranging from 2.92–3.01 Å. In the second Bi+3.25+ site, Bi+3.25+ is bonded to six Se2- atoms to form a mixture of corner and edge-sharing BiSe6 octahedra. The corner-sharing octahedral tilt angles are 3°. There are a spread of Bi–Se bond distances ranging from 2.77–3.16 Å. In the third Bi+3.25+ site, Bi+3.25+ is bonded to six Se2- atoms to form a mixture of corner and edge-sharing BiSe6 octahedra. The corner-sharing octahedra tilt angles range from 3–6°. There are a spread of Bi–Se bond distances ranging from 2.80–3.17 Å. In the fourth Bi+3.25+ site, Bi+3.25+ is bonded to six Se2- atoms to form a mixture of corner and edge-sharing BiSe6 octahedra. The corner-sharing octahedral tilt angles are 5°. There are a spread of Bi–Se bond distances ranging from 2.75–3.32 Å. There are seven inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 3-coordinate geometry to two equivalent Bi+3.25+ and one Se2- atom. The Se–Se bond length is 2.37 Å. In the second Se2- site, Se2- is bonded to two equivalent Cs1+ and three Bi+3.25+ atoms to form distorted SeCs2Bi3 square pyramids that share a cornercorner with one SeBi6 octahedra, corners with six SeCs2Bi3 trigonal bipyramids, edges with two equivalent SeBi6 octahedra, edges with two equivalent SeCs2Bi3 square pyramids, and edges with two SeCs2Bi3 trigonal bipyramids. The corner-sharing octahedral tilt angles are 7°. In the third Se2- site, Se2- is bonded in a distorted T-shaped geometry to three Bi+3.25+ atoms. In the fourth Se2- site, Se2- is bonded to six Bi+3.25+ atoms to form SeBi6 octahedra that share a cornercorner with one SeCs2Bi3 square pyramid, edges with four equivalent SeBi6 octahedra, edges with two equivalent SeCs2Bi3 square pyramids, and edges with two equivalent SeCsBi4 trigonal bipyramids. In the fifth Se2- site, Se2- is bonded in a distorted see-saw-like geometry to one Cs1+ and three Bi+3.25+ atoms. In the sixth Se2- site, Se2- is bonded to two equivalent Cs1+ and three equivalent Bi+3.25+ atoms to form distorted SeCs2Bi3 trigonal bipyramids that share corners with two equivalent SeCs2Bi3 square pyramids, a cornercorner with one SeCsBi4 trigonal bipyramid, an edgeedge with one SeCs2Bi3 square pyramid, and edges with six SeCs2Bi3 trigonal bipyramids. In the seventh Se2- site, Se2- is bonded to one Cs1+ and four Bi+3.25+ atoms to form distorted SeCsBi4 trigonal bipyramids that share corners with four equivalent SeCs2Bi3 square pyramids, corners with three SeCs2Bi3 trigonal bipyramids, edges with two equivalent SeBi6 octahedra, an edgeedge with one SeCs2Bi3 square pyramid, and edges with two equivalent SeCs2Bi3 trigonal bipyramids.