Materials Data on KSnS4 by Materials Project
KSnS4 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. there are two inequivalent K1+ sites. In the first K1+ site, K1+ is bonded in a 6-coordinate geometry to six S1- atoms. There are a spread of K–S bond distances ranging from 3.24–3.42 Å. In the second K1+ site, K1+ is bonded in a 8-coordinate geometry to eight S1- atoms. There are a spread of K–S bond distances ranging from 3.42–3.79 Å. There are two inequivalent Sn3+ sites. In the first Sn3+ site, Sn3+ is bonded to five S1- atoms to form SnS5 trigonal bipyramids that share edges with two equivalent SnS6 octahedra and an edgeedge with one SnS5 trigonal bipyramid. There are a spread of Sn–S bond distances ranging from 2.43–2.92 Å. In the second Sn3+ site, Sn3+ is bonded to six S1- atoms to form SnS6 octahedra that share an edgeedge with one SnS6 octahedra and edges with two equivalent SnS5 trigonal bipyramids. There are a spread of Sn–S bond distances ranging from 2.58–2.64 Å. There are eight inequivalent S1- sites. In the first S1- site, S1- is bonded to two K1+ and two Sn3+ atoms to form a mixture of distorted edge and corner-sharing SK2Sn2 trigonal pyramids. In the second S1- site, S1- is bonded in a water-like geometry to two S1- atoms. There are one shorter (2.04 Å) and one longer (2.09 Å) S–S bond lengths. In the third S1- site, S1- is bonded in a 4-coordinate geometry to two K1+ and two S1- atoms. The S–S bond length is 2.05 Å. In the fourth S1- site, S1- is bonded in a 3-coordinate geometry to two equivalent K1+, one Sn3+, and one S1- atom. In the fifth S1- site, S1- is bonded in a 4-coordinate geometry to two K1+ and two Sn3+ atoms. In the sixth S1- site, S1- is bonded in a 4-coordinate geometry to two K1+ and two equivalent Sn3+ atoms. In the seventh S1- site, S1- is bonded to two K1+ and three Sn3+ atoms to form distorted SK2Sn3 square pyramids that share a cornercorner with one SK2Sn2 trigonal pyramid, an edgeedge with one SK2Sn3 square pyramid, and edges with two equivalent SK2Sn2 trigonal pyramids. In the eighth S1- site, S1- is bonded in a 4-coordinate geometry to two K1+, one Sn3+, and one S1- atom.