Materials Data on K6Sn2S7 by Materials Project
K6Sn2S7 crystallizes in the orthorhombic P2_12_12_1 space group. The structure is three-dimensional. there are six inequivalent K1+ sites. In the first K1+ site, K1+ is bonded in a 6-coordinate geometry to six S2- atoms. There are a spread of K–S bond distances ranging from 3.17–3.59 Å. In the second K1+ site, K1+ is bonded in a 6-coordinate geometry to six S2- atoms. There are a spread of K–S bond distances ranging from 3.22–3.73 Å. In the third K1+ site, K1+ is bonded in a 6-coordinate geometry to six S2- atoms. There are a spread of K–S bond distances ranging from 3.12–3.68 Å. In the fourth K1+ site, K1+ is bonded to six S2- atoms to form distorted KS6 octahedra that share corners with two equivalent KS6 octahedra, a cornercorner with one SnS4 tetrahedra, and edges with three SnS4 tetrahedra. The corner-sharing octahedral tilt angles are 40°. There are a spread of K–S bond distances ranging from 3.20–3.37 Å. In the fifth K1+ site, K1+ is bonded in a 4-coordinate geometry to five S2- atoms. There are a spread of K–S bond distances ranging from 3.20–3.60 Å. In the sixth K1+ site, K1+ is bonded in a 5-coordinate geometry to six S2- atoms. There are a spread of K–S bond distances ranging from 3.24–3.81 Å. There are two inequivalent Sn4+ sites. In the first Sn4+ site, Sn4+ is bonded to four S2- atoms to form SnS4 tetrahedra that share a cornercorner with one KS6 octahedra, a cornercorner with one SnS4 tetrahedra, and an edgeedge with one KS6 octahedra. The corner-sharing octahedral tilt angles are 23°. There are a spread of Sn–S bond distances ranging from 2.38–2.50 Å. In the second Sn4+ site, Sn4+ is bonded to four S2- atoms to form SnS4 tetrahedra that share a cornercorner with one SnS4 tetrahedra and edges with two equivalent KS6 octahedra. There are a spread of Sn–S bond distances ranging from 2.38–2.52 Å. There are seven inequivalent S2- sites. In the first S2- site, S2- is bonded in a 6-coordinate geometry to four K1+ and two Sn4+ atoms. In the second S2- site, S2- is bonded in a 1-coordinate geometry to six K1+ and one Sn4+ atom. In the third S2- site, S2- is bonded in a 7-coordinate geometry to six K1+ and one Sn4+ atom. In the fourth S2- site, S2- is bonded in a 6-coordinate geometry to five K1+ and one Sn4+ atom. In the fifth S2- site, S2- is bonded in a 6-coordinate geometry to five K1+ and one Sn4+ atom. In the sixth S2- site, S2- is bonded in a 6-coordinate geometry to five K1+ and one Sn4+ atom. In the seventh S2- site, S2- is bonded in a 5-coordinate geometry to four K1+ and one Sn4+ atom.