DOE OSTI2020
Cu4Sn7S16 is beta indium sulfide-derived structured and crystallizes in the monoclinic Cm space group. The structure is three-dimensional. there are twelve 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 a spread of Cu–S bond distances ranging from 2.52–2.59 Å. In the second 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°. All Cu–S bond lengths are 2.33 Å. In the third Cu1+ site, Cu1+ is bonded to four S2- atoms to form CuS4 trigonal pyramids that share corners with three CuS6 octahedra and corners with nine SnS6 octahedra. The corner-sharing octahedra tilt angles range from 44–63°. There are three shorter (2.26 Å) and one longer (2.71 Å) Cu–S bond lengths. In the fourth 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 a spread of Cu–S bond distances ranging from 2.53–2.58 Å. In the fifth 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. In the sixth Cu1+ site, Cu1+ is bonded to four S2- atoms to form CuS4 trigonal pyramids that share corners with three CuS6 octahedra and corners with nine SnS6 octahedra. The corner-sharing octahedra tilt angles range from 44–63°. There are a spread of Cu–S bond distances ranging from 2.26–2.71 Å. In the seventh 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 a spread of Cu–S bond distances ranging from 2.52–2.58 Å. In the eighth Cu1+ site, Cu1+ is bonded to four S2- atoms to form distorted CuS4 trigonal pyramids that share corners with three CuS6 octahedra and corners with nine SnS6 octahedra. The corner-sharing octahedra tilt angles range from 37–68°. There are a spread of Cu–S bond distances ranging from 2.24–3.16 Å. In the ninth 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. In the tenth Cu1+ site, Cu1+ is bonded to four S2- atoms to form distorted CuS4 trigonal pyramids that share corners with three CuS6 octahedra and corners with nine SnS6 octahedra. The corner-sharing octahedra tilt angles range from 36–67°. There are three shorter (2.23 Å) and one longer (3.09 Å) Cu–S bond lengths. In the eleventh Cu1+ site, Cu1+ is bonded to four S2- atoms to form distorted CuS4 trigonal pyramids that share corners with three CuS6 octahedra and corners with nine SnS6 octahedra. The corner-sharing octahedra tilt angles range from 37–68°. There are a spread of Cu–S bond distances ranging from 2.24–3.16 Å. In the twelfth Cu1+ site, Cu1+ is bonded to four S2- atoms to form distorted CuS4 trigonal pyramids that share corners with three CuS6 octahedra and corners with nine SnS6 octahedra. The corner-sharing octahedra tilt angles range from 37–68°. There are three shorter (2.25 Å) and one longer (3.16 Å) Cu–S bond lengths. There are fifteen inequivalent Sn4+ sites. In the first 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. In the second 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. In the third Sn4+ site, Sn4+ is bonded to six S2- atoms to form SnS6 octahedra that share corners with three CuS4 tetrahedra and edges with six SnS6 octahedra. There are three shorter (2.56 Å) and three longer (2.65 Å) Sn–S bond lengths. In the fourth Sn4+ site, Sn4+ is bonded to six S2- atoms to form SnS6 octahedra that share corners with two 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 2.57–2.66 Å. In the fifth 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 2.57–2.66 Å. In the sixth 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. In the seventh 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. In the eighth Sn4+ site, Sn4+ is bonded to six S2- atoms to form SnS6 octahedra that share corners with three CuS4 tetrahedra and edges with six SnS6 octahedra. There are a spread of Sn–S bond distances ranging from 2.56–2.65 Å. In the ninth Sn4+ site, Sn4+ is bonded to six S2- atoms to form SnS6 octahedra that share corners with two 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 2.56–2.66 Å. In the tenth 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 2.57–2.66 Å. In the eleventh 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 2.57–2.66 Å. In the twelfth 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. In the thirteenth Sn4+ site, Sn4+ is bonded to six S2- atoms to form SnS6 octahedra that share corners with three CuS4 tetrahedra and edges with six SnS6 octahedra. There are a spread of Sn–S bond distances ranging from 2.56–2.65 Å. In the fourteenth Sn4+ site, Sn4+ is bonded to six S2- atoms to form SnS6 octahedra that share corners with two 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 2.56–2.66 Å. In the fifteenth 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. There are thirty-six inequivalent S2- sites. In the first S2- site, S2- is bonded in a rectangular see-saw-like geometry to one Cu1+ and three 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 rectangular see-saw-like geometry to two Cu1+ and two Sn4+ atoms. In the fourth S2- site, S2- is bonded in a rectangular see-saw-like geometry to one Cu1+ and three Sn4+ atoms. In the fifth S2- site, S2- is bonded in a rectangular see-saw-like geometry to one Cu1+ and three Sn4+ atoms. In the sixth S2- site, S2- is bonded in a distorted T-shaped geometry to three Sn4+ atoms. In the seventh S2- site, S2- is bonded in a distorted T-shaped geometry to three Sn4+ atoms. In the eighth S2- site, S2- is bonded in a distorted rectangular see-saw-like geometry to one Cu1+ and three Sn4+ atoms. In the ninth S2- site, S2- is bonded in a distorted rectangular see-saw-like geometry to one Cu1+ and three Sn4+ atoms. In the tenth S2- site, S2- is bonded in a rectangular see-saw-like geometry to two Cu1+ and two equivalent Sn4+ atoms. In the eleventh S2- site, S2- is bonded in a rectangular see-saw-like geometry to two Cu1+ and two Sn4+ atoms. In the twelfth S2- site, S2- is bonded in a 4-coordinate geometry to one Cu1+ and three Sn4+ atoms. In the thirteenth S2- site, S2- is bonded in a rectangular see-saw-like geometry to two Cu1+ and two Sn4+ atoms. In the fourteenth S2- site, S2- is bonded in a rectangular see-saw-like geometry to one Cu1+ and three Sn4+ atoms. In the fifteenth S2- site, S2- is bonded in a rectangular see-saw-like geometry to two Cu1+ and two equivalent Sn4+ atoms. In the sixteenth S2- site, S2- is bonded in a rectangular see-saw-like geometry to one Cu1+ and three Sn4+ atoms. In the seventeenth S2- site, S2- is bonded in a distorted T-shaped geometry to three Sn4+ atoms. In the eighteenth S2- site, S2- is bonded in a distorted T-shaped geometry to three Sn4+ atoms. In the nineteenth S2- site, S2- is bonded in a distorted rectangular see-saw-like geometry to one Cu1+ and three Sn4+ atoms. In the twentieth S2- site, S2- is bonded in a distorted rectangular see-saw-like geometry to one Cu1+ and three Sn4+ atoms. In the twenty-first S2- site, S2- is bonded in a distorted T-shaped geometry to three Sn4+ atoms. In the twenty-second S2- site, S2- is bonded in a rectangular see-saw-like geometry to two Cu1+ and two equivalent Sn4+ atoms. In the twenty-third S2- site, S2- is bonded in a rectangular see-saw-like geometry to two Cu1+ and two Sn4+ atoms. In the twenty-fourth S2- site, S2- is bonded in a 4-coordinate geometry to one Cu1+ and three Sn4+ atoms. In the twenty-fifth S2- site, S2- is bonded in a rectangular see-saw-like geometry to two Cu1+ and two Sn4+ atoms. In the twenty-sixth S2- site, S2- is bonded in a distorted rectangular see-saw-like geometry to one Cu1+ and three Sn4+ atoms. In the twenty-seventh S2- site, S2- is bonded in a rectangular see-saw-like geometry to two Cu1+ and two equivalent Sn4+ atoms. In the twenty-eighth S2- site, S2- is bonded in a distorted T-shaped geometry to three Sn4+ atoms. In the twenty-ninth S2- site, S2- is bonded in a distorted T-shaped geometry to three Sn4+ atoms. In the thirtieth S2- site, S2- is bonded in a distorted rectangular see-saw-like geometry to one Cu1+ and three Sn4+ atoms. In the thirty-first S2- site, S2- is bonded in a distorted rectangular see-saw-like geometry to one Cu1+ and three Sn4+ atoms. In the thirty-second S2- site, S2- is bonded in a distorted T-shaped geometry to three Sn4+ atoms. In the thirty-third S2- site, S2- is bonded in a 4-coordinate geometry to one Cu1+ and three Sn4+ atoms. In the thirty-fourth S2- site, S2- is bonded in a rectangular see-saw-like geometry to two Cu1+ and two Sn4+ atoms. In the thirty-fifth S2- site, S2- is bonded in a rectangular see-saw-like geometry to two Cu1+ and two