Materials Data on Ta5S8 by Materials Project

Abstract

Ta5S8 crystallizes in the monoclinic C2/m space group. The structure is two-dimensional and consists of two Ta5S8 sheets oriented in the (1, 0, 0) direction. there are three inequivalent Ta+3.20+ sites. In the first Ta+3.20+ site, Ta+3.20+ is bonded to six S2- atoms to form a mixture of distorted corner and edge-sharing TaS6 pentagonal pyramids. The corner-sharing octahedra tilt angles range from 43–45°. There are a spread of Ta–S bond distances ranging from 2.46–2.53 Å. In the second Ta+3.20+ site, Ta+3.20+ is bonded to six S2- atoms to form a mixture of distorted corner, edge, and face-sharing TaS6 pentagonal pyramids. The corner-sharing octahedral tilt angles are 49°. There are a spread of Ta–S bond distances ranging from 2.45–2.54 Å. In the third Ta+3.20+ site, Ta+3.20+ is bonded to six S2- atoms to form a mixture of corner, edge, and face-sharing TaS6 octahedra. There are two shorter (2.45 Å) and four longer (2.53 Å) Ta–S bond lengths. There are four inequivalent S2- sites. In the first S2- site, S2- is bonded to four Ta+3.20+ atoms to form distorted corner-sharing STa4 trigonal pyramids. In the second S2- site, S2- is bonded in a 5-coordinate geometry to five Ta+3.20+ atoms. In the third S2- site, S2- is bonded in a distorted T-shaped geometry to three Ta+3.20+ atoms. In the fourth S2- site, S2- is bonded in a 3-coordinate geometry to three Ta+3.20+ atoms.