Materials Data on Sb4Te7Pb by Materials Project
PbSb4Te7 is MAX Phase-like structured and crystallizes in the trigonal P-3m1 space group. The structure is two-dimensional and consists of one PbSb2Te4 sheet oriented in the (0, 0, 1) direction and one Sb2Te3 sheet oriented in the (0, 0, 1) direction. In the PbSb2Te4 sheet, Pb2+ is bonded to six equivalent Te2- atoms to form PbTe6 octahedra that share corners with six equivalent SbTe6 octahedra, edges with six equivalent PbTe6 octahedra, and edges with six equivalent SbTe6 octahedra. The corner-sharing octahedral tilt angles are 1°. All Pb–Te bond lengths are 3.25 Å. Sb3+ is bonded to six Te2- atoms to form SbTe6 octahedra that share corners with three equivalent PbTe6 octahedra, edges with three equivalent PbTe6 octahedra, and edges with six equivalent SbTe6 octahedra. The corner-sharing octahedral tilt angles are 1°. There are three shorter (3.03 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 in a 6-coordinate geometry to three equivalent Sb3+ atoms. In the second Te2- site, Te2- is bonded to three equivalent Pb2+ and three equivalent Sb3+ atoms to form a mixture of edge and corner-sharing TeSb3Pb3 octahedra. The corner-sharing octahedral tilt angles are 0°. In the Sb2Te3 sheet, Sb3+ is bonded to six Te2- atoms to form a mixture of edge and corner-sharing SbTe6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are three shorter (3.04 Å) and three longer (3.19 Å) Sb–Te bond lengths. There are two inequivalent Te2- sites. In the first Te2- site, Te2- is bonded to six equivalent Sb3+ atoms to form edge-sharing TeSb6 octahedra. In the second Te2- site, Te2- is bonded in a 6-coordinate geometry to three equivalent Sb3+ atoms.