Materials Data on KCu3S2 by Materials Project
KCu3S2 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. K1+ is bonded in a 7-coordinate geometry to seven S2- atoms. There are a spread of K–S bond distances ranging from 3.21–3.35 Å. There are three inequivalent Cu1+ sites. In the first Cu1+ site, Cu1+ is bonded in a bent 120 degrees geometry to two S2- atoms. There are one shorter (2.23 Å) and one longer (2.30 Å) Cu–S bond lengths. In the second Cu1+ site, Cu1+ is bonded in a trigonal planar geometry to three S2- atoms. There are two shorter (2.34 Å) and one longer (2.35 Å) Cu–S bond lengths. In the third Cu1+ site, Cu1+ is bonded in a trigonal non-coplanar geometry to three S2- atoms. There are one shorter (2.29 Å) and two longer (2.36 Å) Cu–S bond lengths. There are two inequivalent S2- sites. In the first S2- site, S2- is bonded in a 4-coordinate geometry to four equivalent K1+ and four Cu1+ atoms. In the second S2- site, S2- is bonded in a 4-coordinate geometry to three equivalent K1+ and four Cu1+ atoms.