Materials Data on Cs3Bi2Br9 by Materials Project

Abstract

Cs3Bi2Br9 crystallizes in the trigonal P-3m1 space group. The structure is three-dimensional. there are two inequivalent Cs1+ sites. In the first Cs1+ site, Cs1+ is bonded to twelve Br1- atoms to form CsBr12 cuboctahedra that share corners with twelve CsBr12 cuboctahedra, faces with six CsBr12 cuboctahedra, and faces with five equivalent BiBr6 octahedra. There are a spread of Cs–Br bond distances ranging from 4.05–4.12 Å. In the second Cs1+ site, Cs1+ is bonded to twelve Br1- atoms to form CsBr12 cuboctahedra that share corners with twelve CsBr12 cuboctahedra, faces with six equivalent CsBr12 cuboctahedra, and faces with six equivalent BiBr6 octahedra. There are six shorter (4.11 Å) and six longer (4.16 Å) Cs–Br bond lengths. Bi3+ is bonded to six Br1- atoms to form BiBr6 octahedra that share corners with three equivalent BiBr6 octahedra and faces with eight CsBr12 cuboctahedra. The corner-sharing octahedral tilt angles are 0°. There are three shorter (2.76 Å) and three longer (3.03 Å) Bi–Br bond lengths. There are two inequivalent Br1- sites. In the first Br1- site, Br1- is bonded in a distorted single-bond geometry to four Cs1+ and one Bi3+ atom. In the second Br1- site, Br1- is bonded to four Cs1+ and two equivalent Bi3+ atoms to form a mixture of distorted corner and face-sharing BrCs4Bi2 octahedra. The corner-sharing octahedra tilt angles range from 0–60°.