Materials Data on KCu2AsS3 by Materials Project
KCu2AsS3 crystallizes in the triclinic P-1 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 3.17–3.54 Å. In the second K1+ site, K1+ is bonded in a 6-coordinate geometry to eight S2- atoms. There are a spread of K–S bond distances ranging from 3.15–3.88 Å. There are four inequivalent Cu1+ sites. In the first Cu1+ site, Cu1+ is bonded to four S2- atoms to form edge-sharing CuS4 tetrahedra. There are a spread of Cu–S bond distances ranging from 2.32–2.46 Å. In the second Cu1+ site, Cu1+ is bonded in a trigonal planar geometry to three S2- atoms. There are a spread of Cu–S bond distances ranging from 2.29–2.31 Å. In the third Cu1+ site, Cu1+ is bonded to four S2- atoms to form edge-sharing CuS4 tetrahedra. There are a spread of Cu–S bond distances ranging from 2.32–2.38 Å. In the fourth Cu1+ site, Cu1+ is bonded in a trigonal non-coplanar geometry to three S2- atoms. There are a spread of Cu–S bond distances ranging from 2.27–2.31 Å. There are two inequivalent As3+ sites. In the first As3+ site, As3+ is bonded in a trigonal non-coplanar geometry to three S2- atoms. There are one shorter (2.31 Å) and two longer (2.33 Å) As–S bond lengths. In the second As3+ site, As3+ is bonded in a trigonal non-coplanar geometry to three S2- atoms. There are a spread of As–S bond distances ranging from 2.32–2.36 Å. There are six inequivalent S2- sites. In the first S2- site, S2- is bonded in a 6-coordinate geometry to three K1+, two Cu1+, and one As3+ atom. In the second S2- site, S2- is bonded in a 6-coordinate geometry to three K1+, two Cu1+, and one As3+ atom. In the third S2- site, S2- is bonded in a 5-coordinate geometry to one K1+, three Cu1+, and one As3+ atom. In the fourth S2- site, S2- is bonded in a 6-coordinate geometry to four K1+, two Cu1+, and one As3+ atom. In the fifth S2- site, S2- is bonded in a 5-coordinate geometry to three K1+, two Cu1+, and one As3+ atom. In the sixth S2- site, S2- is bonded to one K1+, three Cu1+, and one As3+ atom to form distorted edge-sharing SKCu3As trigonal bipyramids.