Materials Data on K3SnSe3 by Materials Project
K3SnSe3 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. there are three inequivalent K1+ sites. In the first K1+ site, K1+ is bonded to six Se2- atoms to form a mixture of edge and corner-sharing KSe6 octahedra. The corner-sharing octahedral tilt angles are 38°. There are a spread of K–Se bond distances ranging from 3.40–3.61 Å. In the second K1+ site, K1+ is bonded in a 6-coordinate geometry to six Se2- atoms. There are a spread of K–Se bond distances ranging from 3.30–3.85 Å. In the third K1+ site, K1+ is bonded in a 7-coordinate geometry to seven Se2- atoms. There are a spread of K–Se bond distances ranging from 3.29–4.01 Å. Sn3+ is bonded in a trigonal non-coplanar geometry to three Se2- atoms. There are two shorter (2.56 Å) and one longer (2.57 Å) Sn–Se bond lengths. There are three inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 6-coordinate geometry to six K1+ and one Sn3+ atom. In the second Se2- site, Se2- is bonded in a 1-coordinate geometry to seven K1+ and one Sn3+ atom. In the third Se2- site, Se2- is bonded in a 7-coordinate geometry to six K1+ and one Sn3+ atom.