DOI: 10.17188/1282601
title: Materials Data on Cu4Sn7S16 by Materials Project

description: Cu4Sn7S16 is beta indium sulfide-derived structured and crystallizes in the trigonal R3m space group. The structure is three-dimensional. there are four inequivalent Cu1+ sites. In the first Cu1+ site, Cu1+ is bonded to six S2- atoms to form CuS6 octahedra that share corners with six CuS4 trigonal pyramids and edges with six SnS6 octahedra. There are three shorter (2.55 Å) and three longer (2.56 Å) Cu–S bond lengths. In the second Cu1+ site, Cu1+ is bonded to four S2- atoms to form CuS4 trigonal pyramids that share corners with three equivalent CuS6 octahedra and corners with nine SnS6 octahedra. The corner-sharing octahedra tilt angles range from 40–66°. There are three shorter (2.25 Å) and one longer (3.02 Å) Cu–S bond lengths. In the third Cu1+ site, Cu1+ is bonded to four S2- atoms to form CuS4 trigonal pyramids that share corners with three equivalent CuS6 octahedra and corners with nine SnS6 octahedra. The corner-sharing octahedra tilt angles range from 39–65°. There are three shorter (2.23 Å) and one longer (2.95 Å) Cu–S bond lengths. In the fourth Cu1+ site, Cu1+ is bonded to four S2- atoms to form CuS4 tetrahedra that share corners with twelve SnS6 octahedra. The corner-sharing octahedra tilt angles range from 54–57°. There are three shorter (2.33 Å) and one longer (2.34 Å) Cu–S bond lengths. There are three inequivalent Sn4+ sites. In the first Sn4+ site, Sn4+ is bonded to six S2- atoms to form SnS6 octahedra that share corners with two equivalent CuS4 tetrahedra, corners with three CuS4 trigonal pyramids, an edgeedge with one CuS6 octahedra, and edges with five SnS6 octahedra. There are a spread of Sn–S bond distances ranging from 2.56–2.65 Å. In the second Sn4+ site, Sn4+ is bonded to six S2- atoms to form SnS6 octahedra that share corners with three equivalent CuS4 tetrahedra and edges with six SnS6 octahedra. There are three shorter (2.55 Å) and three longer (2.64 Å) Sn–S bond lengths. In the third Sn4+ site, Sn4+ is bonded to six S2- atoms to form SnS6 octahedra that share a cornercorner with one CuS4 tetrahedra, corners with three CuS4 trigonal pyramids, an edgeedge with one CuS6 octahedra, and edges with five SnS6 octahedra. There are a spread of Sn–S bond distances ranging from 2.57–2.65 Å. There are eight inequivalent S2- sites. In the first S2- site, S2- is bonded in a distorted T-shaped geometry to three equivalent Sn4+ atoms. In the second S2- site, S2- is bonded in a rectangular see-saw-like geometry to two Cu1+ and two equivalent Sn4+ atoms. In the third S2- site, S2- is bonded in a distorted rectangular see-saw-like geometry to one Cu1+ and three equivalent Sn4+ atoms. In the fourth S2- site, S2- is bonded in a distorted rectangular see-saw-like geometry to one Cu1+ and three Sn4+ atoms. In the fifth S2- site, S2- is bonded in a distorted T-shaped geometry to three Sn4+ atoms. In the sixth S2- site, S2- is bonded in a distorted rectangular see-saw-like geometry to one Cu1+ and three equivalent Sn4+ atoms. In the seventh S2- site, S2- is bonded in a rectangular see-saw-like geometry to two Cu1+ and two equivalent Sn4+ atoms. In the eighth S2- site, S2- is bonded in a rectangular see-saw-like geometry to one Cu1+ and three equivalent Sn4+ atoms.