Materials Data on Bi2(Pb2S3)3 by Materials Project
Pb6Bi2S9 crystallizes in the orthorhombic Cmcm space group. The structure is three-dimensional. there are four inequivalent Pb2+ sites. In the first Pb2+ site, Pb2+ is bonded to six S2- atoms to form PbS6 octahedra that share corners with two equivalent PbS6 octahedra, corners with three equivalent BiS6 octahedra, edges with three equivalent BiS6 octahedra, and edges with nine PbS6 octahedra. The corner-sharing octahedra tilt angles range from 0–5°. There are a spread of Pb–S bond distances ranging from 2.92–3.06 Å. In the second Pb2+ site, Pb2+ is bonded in a 6-coordinate geometry to six S2- atoms. There are two shorter (2.84 Å) and four longer (3.23 Å) Pb–S bond lengths. In the third Pb2+ site, Pb2+ is bonded to six S2- atoms to form PbS6 octahedra that share corners with six PbS6 octahedra, edges with four equivalent BiS6 octahedra, and edges with eight PbS6 octahedra. The corner-sharing octahedra tilt angles range from 1–2°. There are four shorter (2.96 Å) and two longer (2.98 Å) Pb–S bond lengths. In the fourth Pb2+ site, Pb2+ is bonded to six S2- atoms to form PbS6 octahedra that share corners with two PbS6 octahedra, corners with two equivalent BiS6 octahedra, edges with three equivalent BiS6 octahedra, and edges with four PbS6 octahedra. The corner-sharing octahedra tilt angles range from 2–60°. There are a spread of Pb–S bond distances ranging from 2.81–3.19 Å. Bi3+ is bonded to six S2- atoms to form BiS6 octahedra that share corners with five PbS6 octahedra, edges with two equivalent BiS6 octahedra, and edges with eight PbS6 octahedra. The corner-sharing octahedra tilt angles range from 0–9°. There are a spread of Bi–S bond distances ranging from 2.68–3.09 Å. There are five inequivalent S2- sites. In the first S2- site, S2- is bonded to five Pb2+ and one Bi3+ atom to form SBiPb5 octahedra that share corners with four SBiPb5 octahedra, a cornercorner with one SBi2Pb3 square pyramid, edges with ten SBiPb5 octahedra, and edges with two equivalent SBi2Pb3 square pyramids. The corner-sharing octahedra tilt angles range from 0–3°. In the second S2- site, S2- is bonded to four Pb2+ and two equivalent Bi3+ atoms to form SBi2Pb4 octahedra that share corners with three SBiPb5 octahedra, corners with two equivalent SBi2Pb3 square pyramids, a cornercorner with one SPb4 tetrahedra, edges with seven SBiPb5 octahedra, and edges with three equivalent SBi2Pb3 square pyramids. The corner-sharing octahedra tilt angles range from 0–3°. In the third S2- site, S2- is bonded to four Pb2+ atoms to form SPb4 tetrahedra that share corners with two equivalent SBi2Pb4 octahedra, corners with four equivalent SBi2Pb3 square pyramids, and corners with two equivalent SPb4 tetrahedra. The corner-sharing octahedral tilt angles are 5°. In the fourth S2- site, S2- is bonded in a 5-coordinate geometry to four Pb2+ and one Bi3+ atom. In the fifth S2- site, S2- is bonded to three Pb2+ and two equivalent Bi3+ atoms to form SBi2Pb3 square pyramids that share corners with three SBiPb5 octahedra, corners with two equivalent SPb4 tetrahedra, edges with five SBiPb5 octahedra, and edges with two equivalent SBi2Pb3 square pyramids. The corner-sharing octahedra tilt angles range from 3–6°.