Materials Data on Ca3Sn2S7 by Materials Project

Abstract

Ca3Sn2S7 crystallizes in the orthorhombic Cmcm space group. The structure is three-dimensional. there are two inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded in a 5-coordinate geometry to five S2- atoms. There are four shorter (2.87 Å) and one longer (2.90 Å) Ca–S bond lengths. In the second Ca2+ site, Ca2+ is bonded in a 4-coordinate geometry to four S2- atoms. There are a spread of Ca–S bond distances ranging from 2.71–2.85 Å. Sn4+ is bonded to six S2- atoms to form corner-sharing SnS6 octahedra. The corner-sharing octahedra tilt angles range from 32–38°. There are a spread of Sn–S bond distances ranging from 2.52–2.63 Å. There are four inequivalent S2- sites. In the first S2- site, S2- is bonded in a distorted trigonal planar geometry to one Ca2+ and two equivalent Sn4+ atoms. In the second S2- site, S2- is bonded in a 3-coordinate geometry to two equivalent Ca2+ and one Sn4+ atom. In the third S2- site, S2- is bonded to two equivalent Ca2+ and two equivalent Sn4+ atoms to form a mixture of distorted edge and corner-sharing SCa2Sn2 trigonal pyramids. In the fourth S2- site, S2- is bonded to two equivalent Ca2+ and two equivalent Sn4+ atoms to form a mixture of distorted edge and corner-sharing SCa2Sn2 tetrahedra.