DOE OSTI2020
Ta2Tl4S11 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. there are two inequivalent Ta5+ sites. In the first Ta5+ site, Ta5+ is bonded to seven S2- atoms to form distorted face-sharing TaS7 pentagonal bipyramids. There are a spread of Ta–S bond distances ranging from 2.31–2.78 Å. In the second Ta5+ site, Ta5+ is bonded to seven S2- atoms to form distorted face-sharing TaS7 pentagonal bipyramids. There are a spread of Ta–S bond distances ranging from 2.32–2.76 Å. There are four inequivalent Tl3+ sites. In the first Tl3+ site, Tl3+ is bonded in a 4-coordinate geometry to four S2- atoms. There are a spread of Tl–S bond distances ranging from 3.01–3.36 Å. In the second Tl3+ site, Tl3+ is bonded in a distorted rectangular see-saw-like geometry to four S2- atoms. There are a spread of Tl–S bond distances ranging from 3.12–3.28 Å. In the third Tl3+ site, Tl3+ is bonded in a 5-coordinate geometry to six S2- atoms. There are a spread of Tl–S bond distances ranging from 3.11–3.47 Å. In the fourth Tl3+ site, Tl3+ is bonded in a 3-coordinate geometry to two S2- atoms. There are one shorter (3.02 Å) and one longer (3.04 Å) Tl–S bond lengths. There are eleven inequivalent S2- sites. In the first S2- site, S2- is bonded in a 4-coordinate geometry to one Ta5+, two Tl3+, and one S2- atom. The S–S bond length is 2.09 Å. In the second S2- site, S2- is bonded in a 5-coordinate geometry to one Ta5+ and four Tl3+ atoms. In the third S2- site, S2- is bonded in a 4-coordinate geometry to two Ta5+, two equivalent Tl3+, and one S2- atom. The S–S bond length is 2.09 Å. In the fourth S2- site, S2- is bonded in a 1-coordinate geometry to one Ta5+, one Tl3+, and one S2- atom. The S–S bond length is 2.10 Å. In the fifth S2- site, S2- is bonded in a 1-coordinate geometry to one Ta5+ and one S2- atom. In the sixth S2- site, S2- is bonded in a distorted single-bond geometry to one Ta5+, one Tl3+, and one S2- atom. In the seventh S2- site, S2- is bonded in a 1-coordinate geometry to one Ta5+ and one S2- atom. In the eighth S2- site, S2- is bonded to one Ta5+ and three Tl3+ atoms to form distorted edge-sharing STaTl3 trigonal pyramids. In the ninth S2- site, S2- is bonded in a 1-coordinate geometry to one Ta5+, one Tl3+, and one S2- atom. The S–S bond length is 2.08 Å. In the tenth S2- site, S2- is bonded in a 3-coordinate geometry to two Ta5+ and one S2- atom. In the eleventh S2- site, S2- is bonded in a 4-coordinate geometry to two Ta5+ and two Tl3+ atoms.