Materials Data on Ta4S9Br8 by Materials Project
Ta4S9Br8 crystallizes in the tetragonal I4mm space group. The structure is zero-dimensional and consists of two Ta4S9Br8 clusters. Ta5+ is bonded to five S2- and two Br+0.25- atoms to form a mixture of face and corner-sharing TaS5Br2 pentagonal bipyramids. There are a spread of Ta–S bond distances ranging from 2.48–2.54 Å. Both Ta–Br bond lengths are 2.50 Å. There are three inequivalent S2- sites. In the first 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 second S2- site, S2- is bonded in a 2-coordinate geometry to two equivalent Ta5+ and one S2- atom. In the third S2- site, S2- is bonded in a 4-coordinate geometry to four equivalent Ta5+ atoms. There are two inequivalent Br+0.25- sites. In the first Br+0.25- site, Br+0.25- is bonded in a single-bond geometry to one Ta5+ atom. In the second Br+0.25- site, Br+0.25- is bonded in a single-bond geometry to one Ta5+ atom.