DOI: 10.17188/1264972
title: Materials Data on Cu4Bi7S12 by Materials Project

description: Cu4Bi7S12 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. there are two inequivalent Cu1+ sites. In the first Cu1+ site, Cu1+ is bonded to four S2- atoms to form CuS4 tetrahedra that share corners with eight BiS5 square pyramids, corners with two equivalent CuS4 tetrahedra, an edgeedge with one BiS5 square pyramid, and an edgeedge with one CuS4 tetrahedra. There are three shorter (2.34 Å) and one longer (2.38 Å) Cu–S bond lengths. In the second Cu1+ site, Cu1+ is bonded in a distorted trigonal planar geometry to four S2- atoms. There are a spread of Cu–S bond distances ranging from 2.24–3.11 Å. There are four inequivalent Bi+2.86+ sites. In the first Bi+2.86+ site, Bi+2.86+ is bonded to six S2- atoms to form BiS6 octahedra that share corners with two equivalent BiS6 octahedra, corners with four equivalent BiS5 square pyramids, edges with six BiS6 octahedra, and edges with two equivalent BiS5 square pyramids. The corner-sharing octahedral tilt angles are 10°. There are four shorter (2.80 Å) and two longer (2.91 Å) Bi–S bond lengths. In the second Bi+2.86+ site, Bi+2.86+ is bonded to five S2- atoms to form BiS5 square pyramids that share corners with four equivalent CuS4 tetrahedra, edges with four equivalent BiS5 square pyramids, and an edgeedge with one CuS4 tetrahedra. There are a spread of Bi–S bond distances ranging from 2.63–3.12 Å. In the third Bi+2.86+ site, Bi+2.86+ is bonded to five S2- atoms to form distorted BiS5 square pyramids that share corners with two equivalent BiS6 octahedra, corners with four equivalent CuS4 tetrahedra, edges with three BiS6 octahedra, and edges with two equivalent BiS5 square pyramids. The corner-sharing octahedral tilt angles are 11°. There are a spread of Bi–S bond distances ranging from 2.68–3.06 Å. In the fourth Bi+2.86+ site, Bi+2.86+ is bonded to six S2- atoms to form BiS6 octahedra that share a cornercorner with one BiS6 octahedra, edges with six BiS6 octahedra, and edges with two equivalent BiS5 square pyramids. The corner-sharing octahedral tilt angles are 10°. There are a spread of Bi–S bond distances ranging from 2.75–3.05 Å. There are six inequivalent S2- sites. In the first S2- site, S2- is bonded to two equivalent Cu1+ and four Bi+2.86+ atoms to form a mixture of distorted edge and corner-sharing SCu2Bi4 octahedra. The corner-sharing octahedra tilt angles range from 0–3°. In the second S2- site, S2- is bonded in a 3-coordinate geometry to two equivalent Cu1+ and three equivalent Bi+2.86+ atoms. In the third S2- site, S2- is bonded to two equivalent Cu1+ and two equivalent Bi+2.86+ atoms to form distorted SCu2Bi2 trigonal pyramids that share corners with two equivalent SCuBi5 octahedra, corners with two equivalent SCu2Bi2 trigonal pyramids, an edgeedge with one SCuBi5 octahedra, and an edgeedge with one SCu2Bi2 trigonal pyramid. The corner-sharing octahedral tilt angles are 12°. In the fourth S2- site, S2- is bonded in a distorted trigonal non-coplanar geometry to one Cu1+ and two equivalent Bi+2.86+ atoms. In the fifth S2- site, S2- is bonded in a distorted trigonal non-coplanar geometry to three Bi+2.86+ atoms. In the sixth S2- site, S2- is bonded to one Cu1+ and five Bi+2.86+ atoms to form distorted SCuBi5 octahedra that share corners with three SCu2Bi4 octahedra, corners with two equivalent SCu2Bi2 trigonal pyramids, edges with seven SCu2Bi4 octahedra, and an edgeedge with one SCu2Bi2 trigonal pyramid. The corner-sharing octahedra tilt angles range from 0–3°.