Materials Data on Ca2SnS4 by Materials Project

Abstract

Ca2SnS4 is Spinel-like structured and crystallizes in the tetragonal P4_122 space group. The structure is three-dimensional. there are two inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded to six S2- atoms to form CaS6 octahedra that share corners with six equivalent CaS4 tetrahedra, edges with two equivalent CaS6 octahedra, and edges with four equivalent SnS6 octahedra. There are a spread of Ca–S bond distances ranging from 2.82–2.87 Å. In the second Ca2+ site, Ca2+ is bonded to four S2- atoms to form CaS4 tetrahedra that share corners with six equivalent CaS6 octahedra and corners with six equivalent SnS6 octahedra. The corner-sharing octahedra tilt angles range from 51–66°. There are two shorter (2.71 Å) and two longer (2.72 Å) Ca–S bond lengths. Sn4+ is bonded to six S2- atoms to form SnS6 octahedra that share corners with six equivalent CaS4 tetrahedra, edges with two equivalent SnS6 octahedra, and edges with four equivalent CaS6 octahedra. There are a spread of Sn–S bond distances ranging from 2.55–2.67 Å. There are two inequivalent S2- sites. In the first S2- site, S2- is bonded in a rectangular see-saw-like geometry to three Ca2+ and one Sn4+ atom. In the second S2- site, S2- is bonded to two Ca2+ and two equivalent Sn4+ atoms to form a mixture of distorted corner and edge-sharing SCa2Sn2 trigonal pyramids.