Materials Data on K3(Cu4S3)2 by Materials Project
K3Cu8S6 crystallizes in the monoclinic C2/m 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 3.21–3.79 Å. In the second K1+ site, K1+ is bonded in a body-centered cubic geometry to eight S2- atoms. There are four shorter (3.35 Å) and four longer (3.41 Å) K–S bond lengths. There are four inequivalent Cu+1.12+ sites. In the first Cu+1.12+ site, Cu+1.12+ is bonded in a trigonal planar geometry to three S2- atoms. There are two shorter (2.34 Å) and one longer (2.38 Å) Cu–S bond lengths. In the second Cu+1.12+ site, Cu+1.12+ is bonded to four S2- atoms to form a mixture of corner and edge-sharing CuS4 tetrahedra. There are a spread of Cu–S bond distances ranging from 2.37–2.46 Å. In the third Cu+1.12+ site, Cu+1.12+ is bonded in a trigonal planar geometry to three S2- atoms. There are one shorter (2.27 Å) and two longer (2.35 Å) Cu–S bond lengths. In the fourth Cu+1.12+ site, Cu+1.12+ is bonded in a distorted bent 120 degrees geometry to four S2- atoms. There are a spread of Cu–S bond distances ranging from 2.21–2.77 Å. There are three inequivalent S2- sites. In the first S2- site, S2- is bonded in a 6-coordinate geometry to three equivalent K1+ and six Cu+1.12+ atoms. In the second S2- site, S2- is bonded in a 8-coordinate geometry to four K1+ and four Cu+1.12+ atoms. In the third S2- site, S2- is bonded in a 6-coordinate geometry to four K1+ and four Cu+1.12+ atoms.