Materials Data on Ca2Sn3S8 by Materials Project
Ca2Sn3S8 is Ilmenite-like structured and crystallizes in the trigonal R-3m space group. The structure is three-dimensional. Ca2+ is bonded to six equivalent S2- atoms to form distorted CaS6 pentagonal pyramids that share corners with six equivalent SnS6 octahedra, edges with three equivalent SnS6 octahedra, and edges with three equivalent CaS6 pentagonal pyramids. The corner-sharing octahedral tilt angles are 51°. There are three shorter (2.82 Å) and three longer (2.88 Å) Ca–S bond lengths. Sn4+ is bonded to six S2- atoms to form SnS6 octahedra that share corners with four equivalent CaS6 pentagonal pyramids, edges with four equivalent SnS6 octahedra, and edges with two equivalent CaS6 pentagonal pyramids. There are four shorter (2.59 Å) and two longer (2.62 Å) Sn–S bond lengths. There are two inequivalent S2- sites. In the first S2- site, S2- is bonded in a 3-coordinate geometry to three equivalent Sn4+ atoms. In the second S2- site, S2- is bonded to two equivalent Ca2+ and two equivalent Sn4+ atoms to form a mixture of corner and edge-sharing SCa2Sn2 trigonal pyramids.