Materials Data on K(Cu2As)2 by Materials Project

Abstract

K(Cu2As)2 crystallizes in the trigonal R-3m space group. The structure is three-dimensional. K1+ is bonded to six equivalent As3- atoms to form distorted edge-sharing KAs6 octahedra. All K–As bond lengths are 3.37 Å. There are two inequivalent Cu+1.25+ sites. In the first Cu+1.25+ site, Cu+1.25+ is bonded in a 1-coordinate geometry to four equivalent As3- atoms. There are one shorter (2.50 Å) and three longer (2.76 Å) Cu–As bond lengths. In the second Cu+1.25+ site, Cu+1.25+ is bonded in a distorted trigonal non-coplanar geometry to three equivalent As3- atoms. All Cu–As bond lengths are 2.44 Å. As3- is bonded in a 10-coordinate geometry to three equivalent K1+ and seven Cu+1.25+ atoms.