Materials Data on KSnAsS5 by Materials Project
KSnAsS5 crystallizes in the orthorhombic Pbam space group. The structure is three-dimensional. K1+ is bonded in a 6-coordinate geometry to six S2- atoms. There are a spread of K–S bond distances ranging from 3.20–3.75 Å. Sn4+ is bonded to six S2- atoms to form edge-sharing SnS6 octahedra. There are a spread of Sn–S bond distances ranging from 2.53–2.72 Å. As5+ is bonded in a trigonal non-coplanar geometry to three S2- atoms. There are two shorter (2.25 Å) and one longer (2.34 Å) As–S bond lengths. There are four inequivalent S2- sites. In the first S2- site, S2- is bonded in a distorted trigonal non-coplanar geometry to two equivalent Sn4+ and one S2- atom. The S–S bond length is 2.03 Å. In the second S2- site, S2- is bonded to two equivalent K1+, one Sn4+, and one As5+ atom to form a mixture of distorted edge and corner-sharing SK2SnAs trigonal pyramids. In the third S2- site, S2- is bonded in a distorted rectangular see-saw-like geometry to two equivalent K1+ and two equivalent Sn4+ atoms. In the fourth S2- site, S2- is bonded in a distorted water-like geometry to one As5+ and one S2- atom.