K3Cu3As2 crystallizes in the trigonal R-3m space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a 10-coordinate geometry to three equivalent K(2), six equivalent Cu(1), and four equivalent As(1) atoms. In the second K site, K(2) is bonded in a 18-coordinate geometry to six equivalent K(1), six equivalent Cu(1), and six equivalent As(1) atoms. Cu(1) is bonded in a distorted linear geometry to two equivalent K(2), four equivalent K(1), and two equivalent As(1) atoms. As(1) is bonded in a 10-coordinate geometry to three equivalent K(2), four equivalent K(1), and three equivalent Cu(1) atoms.
K3Cu3As2 crystallizes in the trigonal R-3m space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a 10-coordinate geometry to three equivalent K(2), six equivalent Cu(1), and four equivalent As(1) atoms. All K(1)-K(2) bond lengths are 3.68 Å. All K(1)-Cu(1) bond lengths are 3.40 Å. There are three shorter (3.32 Å) and one longer (3.35 Å) K(1)-As(1) bond length. In the second K site, K(2) is bonded in a 18-coordinate geometry to six equivalent K(1), six equivalent Cu(1), and six equivalent As(1) atoms. All K(2)-Cu(1) bond lengths are 3.79 Å. All K(2)-As(1) bond lengths are 3.76 Å. Cu(1) is bonded in a distorted linear geometry to two equivalent K(2), four equivalent K(1), and two equivalent As(1) atoms. Both Cu(1)-As(1) bond lengths are 2.34 Å. As(1) is bonded in a 10-coordinate geometry to three equivalent K(2), four equivalent K(1), and three equivalent Cu(1) atoms.