DOI: 10.17188/1280937
title: Materials Data on Sb8(Pb3S7)3 by Materials Project

description: Pb9Sb8S21 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. there are five inequivalent Pb2+ sites. In the first Pb2+ site, Pb2+ is bonded to seven S2- atoms to form distorted PbS7 pentagonal bipyramids that share a cornercorner with one PbS7 pentagonal bipyramid, corners with two equivalent PbS6 pentagonal pyramids, corners with two SbS5 square pyramids, an edgeedge with one PbS6 octahedra, an edgeedge with one PbS6 pentagonal pyramid, and edges with two SbS5 square pyramids. There are a spread of Pb–S bond distances ranging from 2.89–3.45 Å. In the second Pb2+ site, Pb2+ is bonded to six S2- atoms to form distorted PbS6 pentagonal pyramids that share a cornercorner with one PbS6 octahedra, corners with two equivalent PbS7 pentagonal bipyramids, a cornercorner with one SbS5 square pyramid, an edgeedge with one PbS6 octahedra, an edgeedge with one PbS7 pentagonal bipyramid, and edges with four SbS5 square pyramids. The corner-sharing octahedral tilt angles are 18°. There are a spread of Pb–S bond distances ranging from 2.85–3.35 Å. In the third Pb2+ site, Pb2+ is bonded to six S2- atoms to form distorted PbS6 octahedra that share a cornercorner with one PbS6 pentagonal pyramid, corners with four SbS5 square pyramids, an edgeedge with one PbS6 octahedra, an edgeedge with one PbS7 pentagonal bipyramid, an edgeedge with one PbS6 pentagonal pyramid, and edges with three SbS5 square pyramids. There are a spread of Pb–S bond distances ranging from 2.82–3.34 Å. In the fourth Pb2+ site, Pb2+ is bonded in a 8-coordinate geometry to eight S2- atoms. There are a spread of Pb–S bond distances ranging from 2.86–3.70 Å. In the fifth Pb2+ site, Pb2+ is bonded in a 6-coordinate geometry to six S2- atoms. There are a spread of Pb–S bond distances ranging from 2.69–3.59 Å. There are four inequivalent Sb3+ sites. In the first Sb3+ site, Sb3+ is bonded to five S2- atoms to form distorted SbS5 square pyramids that share corners with two equivalent PbS6 octahedra, a cornercorner with one SbS5 square pyramid, an edgeedge with one PbS6 octahedra, an edgeedge with one PbS7 pentagonal bipyramid, an edgeedge with one PbS6 pentagonal pyramid, and edges with two SbS5 square pyramids. The corner-sharing octahedra tilt angles range from 14–66°. There are a spread of Sb–S bond distances ranging from 2.44–3.14 Å. In the second Sb3+ site, Sb3+ is bonded to five S2- atoms to form distorted SbS5 square pyramids that share a cornercorner with one PbS6 octahedra, a cornercorner with one PbS7 pentagonal bipyramid, a cornercorner with one PbS6 pentagonal pyramid, corners with two SbS5 square pyramids, an edgeedge with one PbS7 pentagonal bipyramid, an edgeedge with one PbS6 pentagonal pyramid, and an edgeedge with one SbS5 square pyramid. The corner-sharing octahedral tilt angles are 66°. There are a spread of Sb–S bond distances ranging from 2.43–3.21 Å. In the third Sb3+ site, Sb3+ is bonded to five S2- atoms to form distorted SbS5 square pyramids that share a cornercorner with one PbS6 octahedra, a cornercorner with one PbS7 pentagonal bipyramid, a cornercorner with one SbS5 square pyramid, edges with two equivalent PbS6 octahedra, edges with two equivalent PbS6 pentagonal pyramids, and edges with two SbS5 square pyramids. The corner-sharing octahedral tilt angles are 12°. There are a spread of Sb–S bond distances ranging from 2.46–3.15 Å. In the fourth Sb3+ site, Sb3+ is bonded in a distorted see-saw-like geometry to four S2- atoms. There are a spread of Sb–S bond distances ranging from 2.45–3.24 Å. There are eleven inequivalent S2- sites. In the first S2- site, S2- is bonded in a 5-coordinate geometry to three Pb2+ and three Sb3+ atoms. In the second S2- site, S2- is bonded in a 1-coordinate geometry to two Pb2+ and one Sb3+ atom. In the third S2- site, S2- is bonded to two Pb2+ and three Sb3+ atoms to form distorted edge-sharing SSb3Pb2 square pyramids. In the fourth S2- site, S2- is bonded to four Pb2+ and one Sb3+ atom to form distorted edge-sharing SSbPb4 square pyramids. In the fifth S2- site, S2- is bonded to three Pb2+ and two Sb3+ atoms to form distorted edge-sharing SSb2Pb3 square pyramids. In the sixth S2- site, S2- is bonded in a 2-coordinate geometry to two Pb2+ and two Sb3+ atoms. In the seventh S2- site, S2- is bonded in a 1-coordinate geometry to three Pb2+ and one Sb3+ atom. In the eighth S2- site, S2- is bonded in a 5-coordinate geometry to three Pb2+ and two equivalent Sb3+ atoms. In the ninth S2- site, S2- is bonded in a distorted water-like geometry to two Pb2+ and two Sb3+ atoms. In the tenth S2- site, S2- is bonded in a distorted water-like geometry to two equivalent Pb2+ and two equivalent Sb3+ atoms. In the eleventh S2- site, S2- is bonded in a 1-coordinate geometry to four Pb2+ and one Sb3+ atom.