K3CuP2S7 crystallizes in the monoclinic P2_1/c space group. There are three inequivalent K sites. In the first K site, K(1) is bonded in a 8-coordinate geometry to one S(1), one S(4), two equivalent S(5), and four equivalent S(2) atoms. In the second K site, K(2) is bonded in a 7-coordinate geometry to one S(1), one S(2), one S(5), one S(6), one S(7), and two equivalent S(4) atoms. In the third K site, K(3) is bonded in a 7-coordinate geometry to one S(4), two equivalent S(3), two equivalent S(6), and two equivalent S(7) atoms. Cu(1) is bonded in a trigonal planar geometry to one S(3), one S(5), and one S(7) atom. There are two inequivalent P sites. In the first P site, P(1) is bonded to one S(1), one S(2), one S(4), and one S(5) atom to form corner-sharing PS4 tetrahedra. In the second P site, P(2) is bonded to one S(1), one S(3), one S(6), and one S(7) atom to form corner-sharing PS4 tetrahedra. There are seven inequivalent S sites. In the first S site, S(6) is bonded in a distorted rectangular see-saw-like geometry to one K(2), two equivalent K(3), and one P(2) atom. In the second S site, S(7) is bonded in a 5-coordinate geometry to one K(2), two equivalent K(3), one Cu(1), and one P(2) atom. In the third S site, S(1) is bonded in a distorted water-like geometry to one K(1), one K(2), one P(1), and one P(2) atom. In the fourth S site, S(2) is bonded in a 6-coordinate geometry to one K(2), four equivalent K(1), and one P(1) atom. In the fifth S site, S(3) is bonded in a 4-coordinate geometry to two equivalent K(3), one Cu(1), and one P(2) atom. In the sixth S site, S(4) is bonded to one K(1), one K(3), two equivalent K(2), and one P(1) atom to form distorted corner-sharing SK4P trigonal bipyramids. In the seventh S site, S(5) is bonded in a 5-coordinate geometry to one K(2), two equivalent K(1), one Cu(1), and one P(1) atom.
K3CuP2S7 crystallizes in the monoclinic P2_1/c space group. There are three inequivalent K sites. In the first K site, K(1) is bonded in a 8-coordinate geometry to one S(1), one S(4), two equivalent S(5), and four equivalent S(2) atoms. The K(1)-S(1) bond length is 3.72 Å. The K(1)-S(4) bond length is 3.17 Å. There is one shorter (3.26 Å) and one longer (3.46 Å) K(1)-S(5) bond length. There are a spread of K(1)-S(2) bond distances ranging from 3.32-3.67 Å. In the second K site, K(2) is bonded in a 7-coordinate geometry to one S(1), one S(2), one S(5), one S(6), one S(7), and two equivalent S(4) atoms. The K(2)-S(1) bond length is 3.53 Å. The K(2)-S(2) bond length is 3.44 Å. The K(2)-S(5) bond length is 3.38 Å. The K(2)-S(6) bond length is 3.21 Å. The K(2)-S(7) bond length is 3.27 Å. There is one shorter (3.36 Å) and one longer (3.40 Å) K(2)-S(4) bond length. In the third K site, K(3) is bonded in a 7-coordinate geometry to one S(4), two equivalent S(3), two equivalent S(6), and two equivalent S(7) atoms. The K(3)-S(4) bond length is 3.43 Å. There is one shorter (3.43 Å) and one longer (3.49 Å) K(3)-S(3) bond length. There is one shorter (3.31 Å) and one longer (3.37 Å) K(3)-S(6) bond length. There is one shorter (3.51 Å) and one longer (3.61 Å) K(3)-S(7) bond length. Cu(1) is bonded in a trigonal planar geometry to one S(3), one S(5), and one S(7) atom. The Cu(1)-S(3) bond length is 2.21 Å. The Cu(1)-S(5) bond length is 2.22 Å. The Cu(1)-S(7) bond length is 2.26 Å. There are two inequivalent P sites. In the first P site, P(1) is bonded to one S(1), one S(2), one S(4), and one S(5) atom to form corner-sharing PS4 tetrahedra. The P(1)-S(1) bond length is 2.16 Å. The P(1)-S(2) bond length is 2.03 Å. The P(1)-S(4) bond length is 2.01 Å. The P(1)-S(5) bond length is 2.06 Å. In the second P site, P(2) is bonded to one S(1), one S(3), one S(6), and one S(7) atom to form corner-sharing PS4 tetrahedra. The P(2)-S(1) bond length is 2.18 Å. The P(2)-S(3) bond length is 2.06 Å. The P(2)-S(6) bond length is 2.01 Å. The P(2)-S(7) bond length is 2.06 Å. There are seven inequivalent S sites. In the first S site, S(6) is bonded in a distorted rectangular see-saw-like geometry to one K(2), two equivalent K(3), and one P(2) atom. In the second S site, S(7) is bonded in a 5-coordinate geometry to one K(2), two equivalent K(3), one Cu(1), and one P(2) atom. In the third S site, S(1) is bonded in a distorted water-like geometry to one K(1), one K(2), one P(1), and one P(2) atom. In the fourth S site, S(2) is bonded in a 6-coordinate geometry to one K(2), four equivalent K(1), and one P(1) atom. In the fifth S site, S(3) is bonded in a 4-coordinate geometry to two equivalent K(3), one Cu(1), and one P(2) atom. In the sixth S site, S(4) is bonded to one K(1), one K(3), two equivalent K(2), and one P(1) atom to form distorted corner-sharing SK4P trigonal bipyramids. In the seventh S site, S(5) is bonded in a 5-coordinate geometry to one K(2), two equivalent K(1), one Cu(1), and one P(1) atom.