Materials Data on SnPb4Se5 by Materials Project

Abstract

Pb4SnSe5 is Caswellsilverite-like structured and crystallizes in the trigonal R-3m space group. The structure is three-dimensional. there are two inequivalent Pb2+ sites. In the first Pb2+ site, Pb2+ is bonded to six Se2- atoms to form PbSe6 octahedra that share corners with three equivalent PbSe6 octahedra, corners with three equivalent SnSe6 octahedra, edges with three equivalent SnSe6 octahedra, and edges with nine PbSe6 octahedra. The corner-sharing octahedra tilt angles range from 0–2°. There are three shorter (3.09 Å) and three longer (3.12 Å) Pb–Se bond lengths. In the second Pb2+ site, Pb2+ is bonded to six Se2- atoms to form a mixture of corner and edge-sharing PbSe6 octahedra. The corner-sharing octahedral tilt angles are 0°. All Pb–Se bond lengths are 3.09 Å. Sn2+ is bonded to six equivalent Se2- atoms to form SnSe6 octahedra that share corners with six equivalent PbSe6 octahedra, edges with six equivalent PbSe6 octahedra, and edges with six equivalent SnSe6 octahedra. The corner-sharing octahedral tilt angles are 2°. All Sn–Se bond lengths are 3.05 Å. There are three inequivalent Se2- sites. In the first Se2- site, Se2- is bonded to three equivalent Pb2+ and three equivalent Sn2+ atoms to form a mixture of corner and edge-sharing SeSn3Pb3 octahedra. The corner-sharing octahedra tilt angles range from 0–1°. In the second Se2- site, Se2- is bonded to six equivalent Pb2+ atoms to form a mixture of corner and edge-sharing SePb6 octahedra. The corner-sharing octahedral tilt angles are 0°. In the third Se2- site, Se2- is bonded to six Pb2+ atoms to form a mixture of corner and edge-sharing SePb6 octahedra. The corner-sharing octahedra tilt angles range from 0–1°.