Materials Data on K2La2Sb2S9 by Materials Project
K2La2Sb2S9 crystallizes in the orthorhombic Pbam space group. The structure is three-dimensional. K1+ is bonded to seven S2- atoms to form a mixture of distorted face and corner-sharing KS7 pentagonal bipyramids. There are a spread of K–S bond distances ranging from 3.22–3.34 Å. La3+ is bonded in a 8-coordinate geometry to eight S2- atoms. There are a spread of La–S bond distances ranging from 2.89–3.05 Å. Sb5+ is bonded in a 6-coordinate geometry to six S2- atoms. There are a spread of Sb–S bond distances ranging from 2.48–3.17 Å. There are five inequivalent S2- sites. In the first S2- site, S2- is bonded to two equivalent K1+, two equivalent La3+, and one Sb5+ atom to form distorted SK2La2Sb square pyramids that share edges with two equivalent SK2Sb4 octahedra and edges with two equivalent SK2La2Sb square pyramids. In the second S2- site, S2- is bonded in a 6-coordinate geometry to two equivalent K1+, two equivalent La3+, one Sb5+, and one S2- atom. The S–S bond length is 2.11 Å. In the third S2- site, S2- is bonded to two equivalent K1+ and four equivalent Sb5+ atoms to form SK2Sb4 octahedra that share edges with two equivalent SK2Sb4 octahedra and edges with four equivalent SK2La2Sb square pyramids. In the fourth S2- site, S2- is bonded in a 5-coordinate geometry to two equivalent K1+, two equivalent La3+, and one S2- atom. In the fifth S2- site, S2- is bonded in a distorted rectangular see-saw-like geometry to two equivalent La3+ and two equivalent Sb5+ atoms.