Materials Data on Ta2S by Materials Project
Ta2S crystallizes in the orthorhombic Pbcm space group. The structure is three-dimensional. there are four inequivalent Ta sites. In the first Ta site, Ta is bonded to twelve Ta atoms to form TaTa12 cuboctahedra that share corners with two equivalent TaTa12 cuboctahedra, corners with two equivalent STa6 pentagonal pyramids, corners with six equivalent STa4 trigonal pyramids, edges with two equivalent STa6 pentagonal pyramids, edges with two equivalent STa4 trigonal pyramids, faces with two equivalent TaTa12 cuboctahedra, faces with two equivalent STa6 pentagonal pyramids, and faces with two equivalent STa4 trigonal pyramids. There are a spread of Ta–Ta bond distances ranging from 2.82–2.99 Å. In the second Ta site, Ta is bonded in a distorted T-shaped geometry to two equivalent Ta and three S atoms. There are a spread of Ta–S bond distances ranging from 2.46–2.59 Å. In the third Ta site, Ta is bonded in a 3-coordinate geometry to two equivalent Ta and three S atoms. There are a spread of Ta–S bond distances ranging from 2.46–2.63 Å. In the fourth Ta site, Ta is bonded in a bent 150 degrees geometry to two equivalent Ta and two equivalent S atoms. Both Ta–S bond lengths are 2.46 Å. There are two inequivalent S sites. In the first S site, S is bonded to four Ta atoms to form distorted STa4 trigonal pyramids that share corners with three equivalent TaTa12 cuboctahedra, corners with four equivalent STa6 pentagonal pyramids, corners with three equivalent STa4 trigonal pyramids, an edgeedge with one TaTa12 cuboctahedra, and a faceface with one TaTa12 cuboctahedra. In the second S site, S is bonded to six Ta atoms to form distorted STa6 pentagonal pyramids that share corners with two equivalent TaTa12 cuboctahedra, corners with eight equivalent STa4 trigonal pyramids, edges with two equivalent TaTa12 cuboctahedra, edges with two equivalent STa6 pentagonal pyramids, and faces with two equivalent TaTa12 cuboctahedra.