Materials Data on K2Y4Sn2S11 by Materials Project
K2Y4Sn2S11 crystallizes in the tetragonal P4/ncc space group. The structure is three-dimensional. there are two inequivalent K1+ sites. In the first K1+ site, K1+ is bonded in a 8-coordinate geometry to eight S2- atoms. There are four shorter (3.37 Å) and four longer (3.68 Å) K–S bond lengths. In the second K1+ site, K1+ is bonded in a 9-coordinate geometry to nine S2- atoms. There are a spread of K–S bond distances ranging from 3.43–3.90 Å. Y3+ is bonded to six S2- atoms to form YS6 octahedra that share corners with three equivalent YS6 octahedra, a cornercorner with one SnS4 tetrahedra, and edges with six equivalent YS6 octahedra. The corner-sharing octahedra tilt angles range from 5–13°. There are a spread of Y–S bond distances ranging from 2.70–2.82 Å. Sn4+ is bonded to four S2- atoms to form SnS4 tetrahedra that share corners with two equivalent YS6 octahedra and an edgeedge with one SnS4 tetrahedra. The corner-sharing octahedral tilt angles are 64°. There are two shorter (2.40 Å) and two longer (2.47 Å) Sn–S bond lengths. There are four inequivalent S2- sites. In the first S2- site, S2- is bonded in a 5-coordinate geometry to one K1+ and four equivalent Y3+ atoms. In the second S2- site, S2- is bonded in a 4-coordinate geometry to two K1+, one Y3+, and one Sn4+ atom. In the third S2- site, S2- is bonded in a 2-coordinate geometry to two equivalent K1+ and two equivalent Sn4+ atoms. In the fourth S2- site, S2- is bonded in a rectangular see-saw-like geometry to one K1+ and four equivalent Y3+ atoms.