Materials Data on Ag2SnBiSe4 by Materials Project

Abstract

Ag2SnBiSe4 is Caswellsilverite-derived structured and crystallizes in the trigonal R3m space group. The structure is three-dimensional. there are two inequivalent Ag1+ sites. In the first Ag1+ site, Ag1+ is bonded to six Se2- atoms to form AgSe6 octahedra that share corners with three equivalent AgSe6 octahedra, corners with three equivalent SnSe6 octahedra, edges with three equivalent SnSe6 octahedra, and edges with nine AgSe6 octahedra. The corner-sharing octahedra tilt angles range from 1–3°. There are three shorter (2.77 Å) and three longer (2.99 Å) Ag–Se bond lengths. In the second Ag1+ site, Ag1+ is bonded to six Se2- atoms to form AgSe6 octahedra that share corners with three equivalent AgSe6 octahedra, corners with three equivalent BiSe6 octahedra, edges with three equivalent BiSe6 octahedra, and edges with nine AgSe6 octahedra. The corner-sharing octahedra tilt angles range from 1–2°. There are three shorter (2.75 Å) and three longer (3.02 Å) Ag–Se bond lengths. Sn3+ is bonded to six Se2- atoms to form SnSe6 octahedra that share corners with three equivalent AgSe6 octahedra, corners with three equivalent BiSe6 octahedra, edges with three equivalent AgSe6 octahedra, edges with three equivalent BiSe6 octahedra, and edges with six equivalent SnSe6 octahedra. The corner-sharing octahedra tilt angles range from 2–3°. There are three shorter (2.86 Å) and three longer (3.11 Å) Sn–Se bond lengths. Bi3+ is bonded to six Se2- atoms to form BiSe6 octahedra that share corners with three equivalent AgSe6 octahedra, corners with three equivalent SnSe6 octahedra, edges with three equivalent AgSe6 octahedra, edges with three equivalent SnSe6 octahedra, and edges with six equivalent BiSe6 octahedra. The corner-sharing octahedral tilt angles are 2°. There are three shorter (2.94 Å) and three longer (3.01 Å) Bi–Se bond lengths. There are four inequivalent Se2- sites. In the first Se2- site, Se2- is bonded to six Ag1+ atoms to form SeAg6 octahedra that share corners with six SeAg3Bi3 octahedra and edges with twelve SeAg6 octahedra. The corner-sharing octahedra tilt angles range from 6–8°. In the second Se2- site, Se2- is bonded to three equivalent Ag1+ and three equivalent Bi3+ atoms to form a mixture of edge and corner-sharing SeAg3Bi3 octahedra. The corner-sharing octahedra tilt angles range from 2–8°. In the third Se2- site, Se2- is bonded to three equivalent Sn3+ and three equivalent Bi3+ atoms to form a mixture of edge and corner-sharing SeSn3Bi3 octahedra. The corner-sharing octahedra tilt angles range from 2–6°. In the fourth Se2- site, Se2- is bonded to three equivalent Ag1+ and three equivalent Sn3+ atoms to form a mixture of edge and corner-sharing SeAg3Sn3 octahedra. The corner-sharing octahedral tilt angles are 6°.