Materials Data on Sn4Te5Pb by Materials Project
PbSn4Te5 is Caswellsilverite-like structured and crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Pb2+ is bonded to six Te2- atoms to form PbTe6 octahedra that share corners with two equivalent SnTe6 octahedra, corners with four equivalent PbTe6 octahedra, edges with four equivalent PbTe6 octahedra, and edges with eight equivalent SnTe6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are four shorter (3.20 Å) and two longer (3.28 Å) Pb–Te bond lengths. There are two inequivalent Sn2+ sites. In the first Sn2+ site, Sn2+ is bonded to six Te2- atoms to form SnTe6 octahedra that share corners with six SnTe6 octahedra, edges with four equivalent PbTe6 octahedra, and edges with eight SnTe6 octahedra. The corner-sharing octahedra tilt angles range from 0–1°. There are a spread of Sn–Te bond distances ranging from 3.20–3.27 Å. In the second Sn2+ site, Sn2+ is bonded to six Te2- atoms to form SnTe6 octahedra that share a cornercorner with one PbTe6 octahedra, corners with five SnTe6 octahedra, and edges with twelve SnTe6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are a spread of Sn–Te bond distances ranging from 3.20–3.27 Å. There are four inequivalent Te2- sites. In the first Te2- site, Te2- is bonded to one Pb2+ and five Sn2+ atoms to form a mixture of corner and edge-sharing TeSn5Pb octahedra. The corner-sharing octahedra tilt angles range from 0–1°. In the second Te2- site, Te2- is bonded to four equivalent Pb2+ and two equivalent Sn2+ atoms to form TeSn2Pb4 octahedra that share corners with six TeSn2Pb4 octahedra and edges with twelve TeSn5Pb octahedra. The corner-sharing octahedral tilt angles are 0°. In the third Te2- site, Te2- is bonded to six Sn2+ atoms to form a mixture of corner and edge-sharing TeSn6 octahedra. The corner-sharing octahedral tilt angles are 0°. In the fourth Te2- site, Te2- is bonded to six Sn2+ atoms to form a mixture of corner and edge-sharing TeSn6 octahedra. The corner-sharing octahedral tilt angles are 0°. The Te–Sn bond length is 3.26 Å.