DOI: 10.17188/1710017
title: Materials Data on Ta8(CuS8)3 by Materials Project

description: Ta8(CuS8)3 crystallizes in the monoclinic Pm space group. The structure is three-dimensional. there are eight inequivalent Ta5+ sites. In the first Ta5+ site, Ta5+ is bonded to six S2- atoms to form distorted TaS6 octahedra that share corners with two equivalent CuS4 tetrahedra, edges with two equivalent TaS6 octahedra, and edges with two equivalent CuS4 tetrahedra. There are a spread of Ta–S bond distances ranging from 2.30–2.69 Å. In the second Ta5+ site, Ta5+ is bonded to six S2- atoms to form distorted TaS6 octahedra that share corners with two equivalent CuS4 tetrahedra, edges with two equivalent TaS6 octahedra, and edges with two equivalent CuS4 tetrahedra. There are a spread of Ta–S bond distances ranging from 2.30–2.70 Å. In the third Ta5+ site, Ta5+ is bonded to six S2- atoms to form distorted TaS6 octahedra that share edges with two equivalent TaS6 octahedra and edges with two equivalent CuS4 tetrahedra. There are a spread of Ta–S bond distances ranging from 2.29–2.72 Å. In the fourth Ta5+ site, Ta5+ is bonded in a 6-coordinate geometry to six S2- atoms. There are a spread of Ta–S bond distances ranging from 2.18–2.79 Å. In the fifth Ta5+ site, Ta5+ is bonded in a 8-coordinate geometry to eight S2- atoms. There are a spread of Ta–S bond distances ranging from 2.51–2.64 Å. In the sixth Ta5+ site, Ta5+ is bonded in a 8-coordinate geometry to eight S2- atoms. There are a spread of Ta–S bond distances ranging from 2.51–2.61 Å. In the seventh Ta5+ site, Ta5+ is bonded in a 8-coordinate geometry to eight S2- atoms. There are a spread of Ta–S bond distances ranging from 2.52–2.62 Å. In the eighth Ta5+ site, Ta5+ is bonded in a 8-coordinate geometry to eight S2- atoms. There are a spread of Ta–S bond distances ranging from 2.52–2.64 Å. There are three inequivalent Cu+2.67+ sites. In the first Cu+2.67+ site, Cu+2.67+ is bonded to four S2- atoms to form CuS4 tetrahedra that share corners with two equivalent CuS4 tetrahedra and edges with two equivalent TaS6 octahedra. There are one shorter (2.30 Å) and three longer (2.31 Å) Cu–S bond lengths. In the second Cu+2.67+ site, Cu+2.67+ is bonded to four S2- atoms to form CuS4 tetrahedra that share corners with two equivalent TaS6 octahedra, corners with two equivalent CuS4 tetrahedra, and edges with two equivalent TaS6 octahedra. The corner-sharing octahedral tilt angles are 64°. There are a spread of Cu–S bond distances ranging from 2.29–2.32 Å. In the third Cu+2.67+ site, Cu+2.67+ is bonded to four S2- atoms to form CuS4 tetrahedra that share corners with two equivalent TaS6 octahedra, corners with two equivalent CuS4 tetrahedra, and edges with two equivalent TaS6 octahedra. The corner-sharing octahedral tilt angles are 65°. There are one shorter (2.29 Å) and three longer (2.30 Å) Cu–S bond lengths. There are twenty-four inequivalent S2- sites. In the first S2- site, S2- is bonded to four Ta5+ atoms to form distorted STa4 trigonal pyramids that share corners with two equivalent STa4 trigonal pyramids, edges with two equivalent STa3Cu tetrahedra, and edges with two equivalent STa4 trigonal pyramids. In the second S2- site, S2- is bonded to four Ta5+ atoms to form distorted STa4 trigonal pyramids that share a cornercorner with one STa3Cu tetrahedra, corners with two equivalent STa4 trigonal pyramids, and edges with two equivalent STa3Cu tetrahedra. In the third S2- site, S2- is bonded to four Ta5+ atoms to form distorted STa4 trigonal pyramids that share a cornercorner with one STa3Cu tetrahedra, corners with two equivalent STa4 trigonal pyramids, and edges with two equivalent STa4 trigonal pyramids. In the fourth S2- site, S2- is bonded in a 4-coordinate geometry to four Ta5+ atoms. In the fifth S2- site, S2- is bonded in an L-shaped geometry to two equivalent Ta5+ atoms. In the sixth S2- site, S2- is bonded in a 3-coordinate geometry to two equivalent Ta5+ and one Cu+2.67+ atom. In the seventh S2- site, S2- is bonded in a 3-coordinate geometry to two equivalent Ta5+ and one Cu+2.67+ atom. In the eighth S2- site, S2- is bonded in a 3-coordinate geometry to two equivalent Ta5+ and one Cu+2.67+ atom. In the ninth S2- site, S2- is bonded in a distorted trigonal non-coplanar geometry to three Ta5+ atoms. In the tenth S2- site, S2- is bonded to three Ta5+ and one Cu+2.67+ atom to form distorted STa3Cu tetrahedra that share corners with two equivalent STa3Cu tetrahedra and a cornercorner with one STa4 trigonal pyramid. In the eleventh S2- site, S2- is bonded to three Ta5+ and one Cu+2.67+ atom to form distorted STa3Cu tetrahedra that share corners with two equivalent STa3Cu tetrahedra, a cornercorner with one STa4 trigonal pyramid, and edges with two equivalent STa4 trigonal pyramids. In the twelfth S2- site, S2- is bonded to three Ta5+ and one Cu+2.67+ atom to form distorted STa3Cu tetrahedra that share corners with two equivalent STa3Cu tetrahedra and edges with two equivalent STa4 trigonal pyramids. In the thirteenth S2- site, S2- is bonded in a 3-coordinate geometry to one Ta5+ and two equivalent Cu+2.67+ atoms. In the fourteenth S2- site, S2- is bonded in a 3-coordinate geometry to one Ta5+ and two equivalent Cu+2.67+ atoms. In the fifteenth S2- site, S2- is bonded in a 3-coordinate geometry to one Ta5+ and two equivalent Cu+2.67+ atoms. In the sixteenth S2- site, S2- is bonded in a single-bond geometry to one Ta5+ atom. In the seventeenth S2- site, S2- is bonded in a 2-coordinate geometry to two equivalent Ta5+ and one S2- atom. The S–S bond length is 2.07 Å. In the eighteenth S2- site, S2- is bonded in a 2-coordinate geometry to two equivalent Ta5+ and one S2- atom. The S–S bond length is 2.06 Å. In the nineteenth S2- site, S2- is bonded in a 2-coordinate geometry to two equivalent Ta5+ and one S2- atom. The S–S bond length is 2.06 Å. In the twentieth S2- site, S2- is bonded in a 2-coordinate geometry to two equivalent Ta5+ and one S2- atom. The S–S bond length is 2.07 Å. In the twenty-first S2- site, S2- is bonded in a 2-coordinate geometry to two equivalent Ta5+ and one S2- atom. In the twenty-second S2- site, S2- is bonded in a 2-coordinate geometry to two equivalent Ta5+ and one S2- atom. In the twenty-third S2- site, S2- is bonded in a 2-coordinate geometry to two equivalent Ta5+ and one S2- atom. In the twenty-fourth S2- site, S2- is bonded in a 2-coordinate geometry to two equivalent Ta5+ and one S2- atom.