Materials Data on GeTe5Pb4 by Materials Project

Abstract

Pb4GeTe5 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 Te2- atoms to form PbTe6 octahedra that share corners with three equivalent PbTe6 octahedra, corners with three equivalent GeTe6 octahedra, edges with three equivalent GeTe6 octahedra, and edges with nine PbTe6 octahedra. The corner-sharing octahedra tilt angles range from 0–6°. There are three shorter (3.27 Å) and three longer (3.28 Å) Pb–Te bond lengths. In the second Pb2+ site, Pb2+ is bonded to six Te2- atoms to form a mixture of corner and edge-sharing PbTe6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are three shorter (3.26 Å) and three longer (3.27 Å) Pb–Te bond lengths. Ge2+ is bonded to six equivalent Te2- atoms to form GeTe6 octahedra that share corners with six equivalent PbTe6 octahedra, edges with six equivalent PbTe6 octahedra, and edges with six equivalent GeTe6 octahedra. The corner-sharing octahedral tilt angles are 6°. All Ge–Te bond lengths are 3.07 Å. There are three inequivalent Te2- sites. In the first Te2- site, Te2- is bonded to three equivalent Pb2+ and three equivalent Ge2+ atoms to form a mixture of corner and edge-sharing TeGe3Pb3 octahedra. The corner-sharing octahedral tilt angles are 0°. In the second Te2- site, Te2- is bonded to six equivalent Pb2+ atoms to form a mixture of corner and edge-sharing TePb6 octahedra. The corner-sharing octahedral tilt angles are 0°. In the third Te2- site, Te2- is bonded to six Pb2+ atoms to form a mixture of corner and edge-sharing TePb6 octahedra. The corner-sharing octahedral tilt angles are 0°.