Materials Data on K2Sn2Se5 by Materials Project
K2Sn2Se5 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. K1+ is bonded in a 8-coordinate geometry to eight Se2- atoms. There are a spread of K–Se bond distances ranging from 3.34–3.99 Å. Sn4+ is bonded to five Se2- atoms to form a mixture of edge and corner-sharing SnSe5 trigonal bipyramids. There are a spread of Sn–Se bond distances ranging from 2.57–2.87 Å. There are three inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 2-coordinate geometry to four equivalent K1+ and two equivalent Sn4+ atoms. In the second Se2- site, Se2- is bonded to three equivalent K1+ and two equivalent Sn4+ atoms to form a mixture of distorted edge and corner-sharing SeK3Sn2 square pyramids. In the third Se2- site, Se2- is bonded in a 3-coordinate geometry to three equivalent K1+ and two equivalent Sn4+ atoms.