Materials Data on K3AsS4 by Materials Project
K3AsS4 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. there are two inequivalent K1+ sites. In the first K1+ site, K1+ is bonded in a 7-coordinate geometry to seven S2- atoms. There are a spread of K–S bond distances ranging from 3.19–3.65 Å. In the second K1+ site, K1+ is bonded to seven S2- atoms to form distorted KS7 pentagonal bipyramids that share corners with two equivalent KS7 pentagonal bipyramids, corners with five equivalent AsS4 tetrahedra, edges with two equivalent KS7 pentagonal bipyramids, and an edgeedge with one AsS4 tetrahedra. There are a spread of K–S bond distances ranging from 3.20–3.70 Å. As5+ is bonded to four S2- atoms to form AsS4 tetrahedra that share corners with five equivalent KS7 pentagonal bipyramids and an edgeedge with one KS7 pentagonal bipyramid. There are a spread of As–S bond distances ranging from 2.19–2.21 Å. There are three inequivalent S2- sites. In the first S2- site, S2- is bonded in a 1-coordinate geometry to five K1+ and one As5+ atom. In the second S2- site, S2- is bonded in a 7-coordinate geometry to six K1+ and one As5+ atom. In the third S2- site, S2- is bonded to five K1+ and one As5+ atom to form edge-sharing SK5As octahedra.