DOI: 10.17188/1311602
title: Materials Data on CaSnS3 by Materials Project

description: CaSnS3 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. there are three inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded to seven S2- atoms to form distorted CaS7 pentagonal bipyramids that share a cornercorner with one SnS5 square pyramid, a cornercorner with one SnS5 trigonal bipyramid, edges with two equivalent CaS7 pentagonal bipyramids, edges with two equivalent SnS5 trigonal bipyramids, and a faceface with one CaS7 hexagonal pyramid. There are a spread of Ca–S bond distances ranging from 2.82–2.94 Å. In the second Ca2+ site, Ca2+ is bonded in a 8-coordinate geometry to eight S2- atoms. There are a spread of Ca–S bond distances ranging from 2.81–3.26 Å. In the third Ca2+ site, Ca2+ is bonded to seven S2- atoms to form distorted CaS7 hexagonal pyramids that share corners with two equivalent CaS7 hexagonal pyramids, corners with three equivalent SnS5 square pyramids, corners with three equivalent SnS5 trigonal bipyramids, an edgeedge with one SnS5 square pyramid, and a faceface with one CaS7 pentagonal bipyramid. There are a spread of Ca–S bond distances ranging from 2.80–3.03 Å. There are three inequivalent Sn4+ sites. In the first Sn4+ site, Sn4+ is bonded to five S2- atoms to form SnS5 trigonal bipyramids that share corners with three equivalent CaS7 hexagonal pyramids, a cornercorner with one CaS7 pentagonal bipyramid, edges with two equivalent CaS7 pentagonal bipyramids, and an edgeedge with one SnS5 square pyramid. There are a spread of Sn–S bond distances ranging from 2.49–2.71 Å. In the second Sn4+ site, Sn4+ is bonded in a distorted T-shaped geometry to three S2- atoms. There are one shorter (2.57 Å) and two longer (2.75 Å) Sn–S bond lengths. In the third Sn4+ site, Sn4+ is bonded to five S2- atoms to form distorted SnS5 square pyramids that share corners with three equivalent CaS7 hexagonal pyramids, a cornercorner with one CaS7 pentagonal bipyramid, an edgeedge with one CaS7 hexagonal pyramid, and an edgeedge with one SnS5 trigonal bipyramid. There are a spread of Sn–S bond distances ranging from 2.68–2.97 Å. There are nine inequivalent S2- sites. In the first S2- site, S2- is bonded in a rectangular see-saw-like geometry to two equivalent Ca2+ and two Sn4+ atoms. In the second S2- site, S2- is bonded in a 4-coordinate geometry to three Ca2+ and one S2- atom. The S–S bond length is 2.09 Å. In the third S2- site, S2- is bonded in a distorted see-saw-like geometry to three Ca2+ and one Sn4+ atom. In the fourth S2- site, S2- is bonded to two equivalent Ca2+ and two Sn4+ atoms to form distorted SCa2Sn2 tetrahedra that share corners with three SCa2Sn2 tetrahedra and an edgeedge with one SCaSn3 trigonal pyramid. In the fifth S2- site, S2- is bonded in a 5-coordinate geometry to three Ca2+, one Sn4+, and one S2- atom. The S–S bond length is 2.15 Å. In the sixth S2- site, S2- is bonded in a 5-coordinate geometry to three Ca2+, one Sn4+, and one S2- atom. In the seventh S2- site, S2- is bonded to one Ca2+ and three Sn4+ atoms to form a mixture of distorted edge and corner-sharing SCaSn3 trigonal pyramids. In the eighth S2- site, S2- is bonded in a 5-coordinate geometry to three Ca2+, one Sn4+, and one S2- atom. In the ninth S2- site, S2- is bonded to two equivalent Ca2+ and two Sn4+ atoms to form distorted SCa2Sn2 tetrahedra that share a cornercorner with one SCa2Sn2 tetrahedra, corners with two equivalent SCaSn3 trigonal pyramids, and an edgeedge with one SCa2Sn2 tetrahedra.