DOI: 10.17188/1311693
title: Materials Data on Ca2SnS4 by Materials Project

description: Ca2SnS4 crystallizes in the orthorhombic Pna2_1 space group. The structure is three-dimensional. there are four 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 CaS6 pentagonal pyramid, corners with two equivalent SnS4 tetrahedra, corners with two equivalent SnS5 trigonal bipyramids, edges with two equivalent CaS6 pentagonal pyramids, an edgeedge with one SnS4 tetrahedra, and an edgeedge with one SnS5 trigonal bipyramid. There are a spread of Ca–S bond distances ranging from 2.88–3.38 Å. In the second Ca2+ site, Ca2+ is bonded in a 7-coordinate geometry to seven S2- atoms. There are a spread of Ca–S bond distances ranging from 2.90–3.13 Å. In the third Ca2+ site, Ca2+ is bonded in a 6-coordinate geometry to six S2- atoms. There are a spread of Ca–S bond distances ranging from 2.81–3.33 Å. In the fourth Ca2+ site, Ca2+ is bonded to six S2- atoms to form distorted CaS6 pentagonal pyramids that share a cornercorner with one CaS7 pentagonal bipyramid, corners with three equivalent SnS4 tetrahedra, a cornercorner with one SnS5 trigonal bipyramid, edges with two equivalent CaS7 pentagonal bipyramids, and an edgeedge with one SnS5 trigonal bipyramid. There are a spread of Ca–S bond distances ranging from 2.86–2.92 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 corners with two equivalent CaS7 pentagonal bipyramids, corners with three equivalent CaS6 pentagonal pyramids, a cornercorner with one SnS5 trigonal bipyramid, and an edgeedge with one CaS7 pentagonal bipyramid. There are a spread of Sn–S bond distances ranging from 2.36–2.42 Å. In the second Sn4+ site, Sn4+ is bonded to five S2- atoms to form distorted SnS5 trigonal bipyramids that share corners with two equivalent CaS7 pentagonal bipyramids, a cornercorner with one CaS6 pentagonal pyramid, a cornercorner with one SnS4 tetrahedra, an edgeedge with one CaS7 pentagonal bipyramid, and an edgeedge with one CaS6 pentagonal pyramid. There are a spread of Sn–S bond distances ranging from 2.40–2.99 Å. There are eight inequivalent S2- sites. In the first S2- site, S2- is bonded to three Ca2+ and one Sn4+ atom to form distorted SCa3Sn trigonal pyramids that share corners with four SCa3Sn tetrahedra, a cornercorner with one SCa4Sn trigonal bipyramid, an edgeedge with one SCa3Sn tetrahedra, and an edgeedge with one SCa4Sn trigonal bipyramid. In the second S2- site, S2- is bonded to four Ca2+ and one Sn4+ atom to form a mixture of distorted edge and corner-sharing SCa4Sn trigonal bipyramids. In the third S2- site, S2- is bonded in a 5-coordinate geometry to three Ca2+ and two Sn4+ atoms. In the fourth S2- site, S2- is bonded in a distorted see-saw-like geometry to three Ca2+ and one Sn4+ atom. In the fifth S2- site, S2- is bonded in a 5-coordinate geometry to four Ca2+ and one Sn4+ atom. In the sixth S2- site, S2- is bonded to three Ca2+ and one Sn4+ atom to form distorted SCa3Sn tetrahedra that share corners with three equivalent SCa3Sn tetrahedra, a cornercorner with one SCa4Sn trigonal bipyramid, a cornercorner with one SCa3Sn trigonal pyramid, an edgeedge with one SCa4Sn trigonal bipyramid, and an edgeedge with one SCa3Sn trigonal pyramid. In the seventh S2- site, S2- is bonded to three Ca2+ and one Sn4+ atom to form SCa3Sn tetrahedra that share corners with three equivalent SCa3Sn tetrahedra, a cornercorner with one SCa4Sn trigonal bipyramid, corners with three equivalent SCa3Sn trigonal pyramids, and an edgeedge with one SCa4Sn trigonal bipyramid. In the eighth S2- site, S2- is bonded in a 4-coordinate geometry to three Ca2+ and one Sn4+ atom.