Materials Data on Sn2PbSe3 by Materials Project
PbSn2Se3 is Caswellsilverite-like structured and crystallizes in the trigonal P-3m1 space group. The structure is three-dimensional. Pb2+ is bonded to six equivalent Se2- atoms to form PbSe6 octahedra that share corners with six equivalent SnSe6 octahedra, edges with six equivalent PbSe6 octahedra, and edges with six equivalent SnSe6 octahedra. The corner-sharing octahedral tilt angles are 2°. All Pb–Se bond lengths are 3.09 Å. Sn2+ is bonded to six Se2- atoms to form SnSe6 octahedra that share corners with three equivalent PbSe6 octahedra, corners with three equivalent SnSe6 octahedra, edges with three equivalent PbSe6 octahedra, and edges with nine equivalent SnSe6 octahedra. The corner-sharing octahedra tilt angles range from 0–2°. There are three shorter (3.03 Å) and three longer (3.04 Å) Sn–Se bond lengths. There are two 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 octahedral tilt angles are 0°. In the second Se2- site, Se2- is bonded to six equivalent Sn2+ atoms to form a mixture of corner and edge-sharing SeSn6 octahedra. The corner-sharing octahedral tilt angles are 0°.