Materials Data on K2Sn2S5 by Materials Project

K2Sn2S5 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. K1+ is bonded in a 8-coordinate geometry to eight S2- atoms. There are a spread of K–S bond distances ranging from 3.16–3.73 Å. Sn4+ is bonded to five S2- atoms to form a mixture of edge and corner-sharing SnS5 trigonal bipyramids. There are a spread of Sn–S bond distances ranging from 2.43–2.68 Å. There are three inequivalent S2- sites. In the first S2- site, S2- is bonded to three equivalent K1+ and two equivalent Sn4+ atoms to form a mixture of distorted edge and corner-sharing SK3Sn2 square pyramids. In the second S2- site, S2- is bonded in a distorted bent 120 degrees geometry to four equivalent K1+ and two equivalent Sn4+ atoms. In the third S2- site, S2- is bonded in a 4-coordinate geometry to three equivalent K1+ and two equivalent Sn4+ atoms.