Materials Data on Cu9S16 by Materials Project
Cu9S16 crystallizes in the trigonal R3m space group. The structure is two-dimensional and consists of three Cu9S16 sheets oriented in the (0, 0, 1) direction. there are nine inequivalent Cu+2.67+ sites. In the first Cu+2.67+ site, Cu+2.67+ is bonded to six S+1.50- atoms to form CuS6 octahedra that share corners with six equivalent SS12 cuboctahedra, edges with six equivalent CuS6 octahedra, and a faceface with one SS12 cuboctahedra. There are three shorter (2.41 Å) and three longer (2.42 Å) Cu–S bond lengths. In the second Cu+2.67+ site, Cu+2.67+ is bonded to four S+1.50- atoms to form CuS4 tetrahedra that share corners with three equivalent SS12 cuboctahedra, corners with seven CuS4 tetrahedra, and edges with three equivalent SS12 cuboctahedra. There are one shorter (2.13 Å) and three longer (2.23 Å) Cu–S bond lengths. In the third Cu+2.67+ site, Cu+2.67+ is bonded to four S+1.50- atoms to form corner-sharing CuS4 tetrahedra. There are one shorter (2.13 Å) and three longer (2.22 Å) Cu–S bond lengths. In the fourth Cu+2.67+ site, Cu+2.67+ is bonded to four S+1.50- atoms to form corner-sharing CuS4 tetrahedra. There are three shorter (2.20 Å) and one longer (2.22 Å) Cu–S bond lengths. In the fifth Cu+2.67+ site, Cu+2.67+ is bonded to four S+1.50- atoms to form corner-sharing CuS4 tetrahedra. There are three shorter (2.20 Å) and one longer (2.21 Å) Cu–S bond lengths. In the sixth Cu+2.67+ site, Cu+2.67+ is bonded to four S+1.50- atoms to form corner-sharing CuS4 tetrahedra. All Cu–S bond lengths are 2.20 Å. In the seventh Cu+2.67+ site, Cu+2.67+ is bonded to four S+1.50- atoms to form corner-sharing CuS4 tetrahedra. All Cu–S bond lengths are 2.20 Å. In the eighth Cu+2.67+ site, Cu+2.67+ is bonded to four S+1.50- atoms to form corner-sharing CuS4 tetrahedra. There are one shorter (2.19 Å) and three longer (2.21 Å) Cu–S bond lengths. In the ninth Cu+2.67+ site, Cu+2.67+ is bonded to four S+1.50- atoms to form corner-sharing CuS4 tetrahedra. There are three shorter (2.20 Å) and one longer (2.23 Å) Cu–S bond lengths. There are sixteen inequivalent S+1.50- sites. In the first S+1.50- site, S+1.50- is bonded in a trigonal non-coplanar geometry to three equivalent Cu+2.67+ atoms. In the second S+1.50- site, S+1.50- is bonded in a 3-coordinate geometry to three equivalent Cu+2.67+ atoms. In the third S+1.50- site, S+1.50- is bonded in a 3-coordinate geometry to three equivalent Cu+2.67+ and three equivalent S+1.50- atoms. All S–S bond lengths are 3.81 Å. In the fourth S+1.50- site, S+1.50- is bonded to twelve S+1.50- atoms to form SS12 cuboctahedra that share corners with nine SS12 cuboctahedra, corners with six equivalent CuS6 octahedra, edges with fifteen SS12 cuboctahedra, faces with twelve SS12 cuboctahedra, and a faceface with one CuS6 octahedra. The corner-sharing octahedral tilt angles are 49°. There are three shorter (3.53 Å) and six longer (3.62 Å) S–S bond lengths. In the fifth S+1.50- site, S+1.50- is bonded to twelve S+1.50- atoms to form a mixture of edge, face, and corner-sharing SS12 cuboctahedra. There are three shorter (3.55 Å) and six longer (3.62 Å) S–S bond lengths. In the sixth S+1.50- site, S+1.50- is bonded to twelve S+1.50- atoms to form a mixture of edge, face, and corner-sharing SS12 cuboctahedra. There are a spread of S–S bond distances ranging from 3.50–3.62 Å. In the seventh S+1.50- site, S+1.50- is bonded to twelve S+1.50- atoms to form SS12 cuboctahedra that share corners with nine SS12 cuboctahedra, corners with three equivalent CuS4 tetrahedra, edges with fifteen SS12 cuboctahedra, edges with three equivalent CuS4 tetrahedra, and faces with twelve SS12 cuboctahedra. There are three shorter (3.61 Å) and six longer (3.62 Å) S–S bond lengths. In the eighth S+1.50- site, S+1.50- is bonded to twelve S+1.50- atoms to form a mixture of edge, face, and corner-sharing SS12 cuboctahedra. All S–S bond lengths are 3.62 Å. In the ninth S+1.50- site, S+1.50- is bonded in a trigonal non-coplanar geometry to three equivalent Cu+2.67+ and three equivalent S+1.50- atoms. In the tenth S+1.50- site, S+1.50- is bonded in a linear geometry to two Cu+2.67+ atoms. In the eleventh S+1.50- site, S+1.50- is bonded to four Cu+2.67+ atoms to form corner-sharing SCu4 tetrahedra. In the twelfth S+1.50- site, S+1.50- is bonded to four Cu+2.67+ atoms to form corner-sharing SCu4 tetrahedra. In the thirteenth S+1.50- site, S+1.50- is bonded to four Cu+2.67+ atoms to form corner-sharing SCu4 tetrahedra. In the fourteenth S+1.50- site, S+1.50- is bonded to four Cu+2.67+ atoms to form corner-sharing SCu4 tetrahedra. In the fifteenth S+1.50- site, S+1.50- is bonded to four Cu+2.67+ atoms to form corner-sharing SCu4 tetrahedra. In the sixteenth S+1.50- site, S+1.50- is bonded to four Cu+2.67+ atoms to form corner-sharing SCu4 tetrahedra.