Materials Data on CaSn3S7 by Materials Project
CaSn3S7 crystallizes in the orthorhombic Pmmn space group. The structure is three-dimensional. Ca2+ is bonded in a 2-coordinate geometry to eight S2- atoms. There are a spread of Ca–S bond distances ranging from 2.73–3.53 Å. There are two inequivalent Sn4+ sites. In the first Sn4+ site, Sn4+ is bonded in a 5-coordinate geometry to five S2- atoms. There are a spread of Sn–S bond distances ranging from 2.33–2.61 Å. In the second Sn4+ site, Sn4+ is bonded in a 5-coordinate geometry to five S2- atoms. There are one shorter (2.33 Å) and four longer (2.65 Å) Sn–S bond lengths. There are three inequivalent S2- sites. In the first S2- site, S2- is bonded in a distorted single-bond geometry to two equivalent Ca2+ and one Sn4+ atom. In the second S2- site, S2- is bonded in a bent 120 degrees geometry to one Ca2+ and one Sn4+ atom. In the third S2- site, S2- is bonded to one Ca2+ and three Sn4+ atoms to form a mixture of distorted edge and corner-sharing SCaSn3 tetrahedra.