Materials Data on Bi2Sb2Te3 by Materials Project
(BiSb)2Te3 is Caswellsilverite-like structured and crystallizes in the trigonal R-3m space group. The structure is three-dimensional. Bi3+ is bonded to three equivalent Bi3+ and three equivalent Te2- atoms to form distorted BiBi3Te3 octahedra that share corners with three equivalent SbTe6 octahedra, corners with three equivalent TeBi3Sb3 octahedra, edges with three equivalent SbTe6 octahedra, edges with three equivalent TeBi3Sb3 octahedra, and edges with six equivalent BiBi3Te3 octahedra. The corner-sharing octahedral tilt angles are 10°. All Bi–Bi bond lengths are 3.08 Å. All Bi–Te bond lengths are 3.52 Å. Sb is bonded to six Te2- atoms to form SbTe6 octahedra that share corners with three equivalent BiBi3Te3 octahedra, corners with three equivalent SbTe6 octahedra, edges with three equivalent BiBi3Te3 octahedra, and edges with nine equivalent SbTe6 octahedra. The corner-sharing octahedra tilt angles range from 0–10°. There are three shorter (3.06 Å) and three longer (3.21 Å) Sb–Te bond lengths. There are two inequivalent Te2- sites. In the first Te2- site, Te2- is bonded to three equivalent Bi3+ and three equivalent Sb atoms to form TeBi3Sb3 octahedra that share corners with three equivalent BiBi3Te3 octahedra, corners with three equivalent TeSb6 octahedra, edges with three equivalent BiBi3Te3 octahedra, and edges with nine TeBi3Sb3 octahedra. The corner-sharing octahedra tilt angles range from 4–10°. In the second Te2- site, Te2- is bonded to six equivalent Sb atoms to form a mixture of edge and corner-sharing TeSb6 octahedra. The corner-sharing octahedral tilt angles are 4°.