K3Th2Cu3S7 crystallizes in the orthorhombic Cmcm space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a 7-coordinate geometry to one S(3), two equivalent S(4), and four equivalent S(2) atoms. In the second K site, K(2) is bonded in a 8-coordinate geometry to two equivalent S(1), two equivalent S(4), and four equivalent S(3) atoms. Th(1) is bonded to one S(1), one S(2), two equivalent S(3), and two equivalent S(4) atoms to form ThS6 octahedra that share  a cornercorner with one Th(1)S6 octahedra,  a cornercorner with one Cu(1)S4 tetrahedra, edges with two equivalent Th(1)S6 octahedra, edges with two equivalent Cu(1)S4 tetrahedra, and edges with two equivalent Cu(2)S4 tetrahedra. The corner-sharing octahedral tilt angles are 36°. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to one S(4) and three equivalent S(2) atoms to form CuS4 tetrahedra that share  a cornercorner with one Th(1)S6 octahedra, corners with two equivalent Cu(1)S4 tetrahedra, edges with two equivalent Th(1)S6 octahedra, and edges with two equivalent Cu(1)S4 tetrahedra. The corner-sharing octahedral tilt angles are 59°. In the second Cu site, Cu(2) is bonded to two equivalent S(1) and two equivalent S(3) atoms to form CuS4 tetrahedra that share corners with two equivalent Cu(2)S4 tetrahedra and edges with four equivalent Th(1)S6 octahedra. There are four inequivalent S sites. In the first S site, S(1) is bonded in a 6-coordinate geometry to two equivalent K(2), two equivalent Th(1), and two equivalent Cu(2) atoms. In the second S site, S(2) is bonded in a 8-coordinate geometry to four equivalent K(1), one Th(1), and three equivalent Cu(1) atoms. In the third S site, S(3) is bonded to one K(1), two equivalent K(2), two equivalent Th(1), and one Cu(2) atom to form a mixture of distorted corner, face, and edge-sharing SK3Th2Cu octahedra. The corner-sharing octahedral tilt angles range from 4-69°. In the fourth S site, S(4) is bonded to one K(2), two equivalent K(1), two equivalent Th(1), and one Cu(1) atom to form a mixture of distorted corner and edge-sharing SK3Th2Cu octahedra. The corner-sharing octahedral tilt angles range from 4-53°.
K3Th2Cu3S7 crystallizes in the orthorhombic Cmcm space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a 7-coordinate geometry to one S(3), two equivalent S(4), and four equivalent S(2) atoms. The K(1)-S(3) bond length is 3.17 Å. Both K(1)-S(4) bond lengths are 3.16 Å. There are two shorter (3.40 Å) and two longer (3.45 Å) K(1)-S(2) bond lengths. In the second K site, K(2) is bonded in a 8-coordinate geometry to two equivalent S(1), two equivalent S(4), and four equivalent S(3) atoms. Both K(2)-S(1) bond lengths are 3.27 Å. Both K(2)-S(4) bond lengths are 3.60 Å. All K(2)-S(3) bond lengths are 3.40 Å. Th(1) is bonded to one S(1), one S(2), two equivalent S(3), and two equivalent S(4) atoms to form ThS6 octahedra that share  a cornercorner with one Th(1)S6 octahedra,  a cornercorner with one Cu(1)S4 tetrahedra, edges with two equivalent Th(1)S6 octahedra, edges with two equivalent Cu(1)S4 tetrahedra, and edges with two equivalent Cu(2)S4 tetrahedra. The corner-sharing octahedral tilt angles are 36°. The Th(1)-S(1) bond length is 2.81 Å. The Th(1)-S(2) bond length is 2.79 Å. Both Th(1)-S(3) bond lengths are 2.80 Å. Both Th(1)-S(4) bond lengths are 2.77 Å. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to one S(4) and three equivalent S(2) atoms to form CuS4 tetrahedra that share  a cornercorner with one Th(1)S6 octahedra, corners with two equivalent Cu(1)S4 tetrahedra, edges with two equivalent Th(1)S6 octahedra, and edges with two equivalent Cu(1)S4 tetrahedra. The corner-sharing octahedral tilt angles are 59°. The Cu(1)-S(4) bond length is 2.34 Å. There are two shorter (2.44 Å) and one longer (2.45 Å) Cu(1)-S(2) bond length. In the second Cu site, Cu(2) is bonded to two equivalent S(1) and two equivalent S(3) atoms to form CuS4 tetrahedra that share corners with two equivalent Cu(2)S4 tetrahedra and edges with four equivalent Th(1)S6 octahedra. Both Cu(2)-S(1) bond lengths are 2.42 Å. Both Cu(2)-S(3) bond lengths are 2.33 Å. There are four inequivalent S sites. In the first S site, S(1) is bonded in a 6-coordinate geometry to two equivalent K(2), two equivalent Th(1), and two equivalent Cu(2) atoms. In the second S site, S(2) is bonded in a 8-coordinate geometry to four equivalent K(1), one Th(1), and three equivalent Cu(1) atoms. In the third S site, S(3) is bonded to one K(1), two equivalent K(2), two equivalent Th(1), and one Cu(2) atom to form a mixture of distorted corner, face, and edge-sharing SK3Th2Cu octahedra. The corner-sharing octahedral tilt angles range from 4-69°. In the fourth S site, S(4) is bonded to one K(2), two equivalent K(1), two equivalent Th(1), and one Cu(1) atom to form a mixture of distorted corner and edge-sharing SK3Th2Cu octahedra. The corner-sharing octahedral tilt angles range from 4-53°.