NbCr3(CuS4)2 crystallizes in the monoclinic P2/m space group. Nb(1) is bonded to two equivalent S(2) and four equivalent S(3) atoms to form NbS6 octahedra that share corners with four equivalent Cu(1)S6 octahedra, edges with two equivalent Cr(2)S6 octahedra, edges with four equivalent Cr(1)S6 octahedra, and faces with two equivalent Cu(2)S6 octahedra. The corner-sharing octahedral tilt angles are 50°. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to two equivalent S(1), two equivalent S(2), and two equivalent S(3) atoms to form CrS6 octahedra that share corners with four equivalent Cu(1)S6 octahedra, corners with four equivalent Cu(2)S6 octahedra, edges with two equivalent Nb(1)S6 octahedra, edges with two equivalent Cr(1)S6 octahedra, and edges with two equivalent Cr(2)S6 octahedra. The corner-sharing octahedral tilt angles range from 44-49°. In the second Cr site, Cr(2) is bonded to two equivalent S(1) and four equivalent S(3) atoms to form CrS6 octahedra that share corners with four equivalent Cu(2)S6 octahedra, edges with two equivalent Nb(1)S6 octahedra, edges with four equivalent Cr(1)S6 octahedra, and faces with two equivalent Cu(1)S6 octahedra. The corner-sharing octahedral tilt angles are 50°. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to two equivalent S(1) and four equivalent S(3) atoms to form CuS6 octahedra that share corners with four equivalent Nb(1)S6 octahedra, corners with eight equivalent Cr(1)S6 octahedra, edges with two equivalent Cu(2)S6 octahedra, and faces with two equivalent Cr(2)S6 octahedra. The corner-sharing octahedral tilt angles range from 44-50°. In the second Cu site, Cu(2) is bonded to two equivalent S(2) and four equivalent S(3) atoms to form CuS6 octahedra that share corners with four equivalent Cr(2)S6 octahedra, corners with eight equivalent Cr(1)S6 octahedra, edges with two equivalent Cu(1)S6 octahedra, and faces with two equivalent Nb(1)S6 octahedra. The corner-sharing octahedral tilt angles range from 47-50°. There are three inequivalent S sites. In the first S site, S(1) is bonded in a rectangular see-saw-like geometry to one Cr(2), two equivalent Cr(1), and one Cu(1) atom. In the second S site, S(2) is bonded in a rectangular see-saw-like geometry to one Nb(1), two equivalent Cr(1), and one Cu(2) atom. In the third S site, S(3) is bonded to one Nb(1), one Cr(1), one Cr(2), one Cu(1), and one Cu(2) atom to form a mixture of distorted corner and edge-sharing SNbCr2Cu2 square pyramids.
NbCr3(CuS4)2 crystallizes in the monoclinic P2/m space group. Nb(1) is bonded to two equivalent S(2) and four equivalent S(3) atoms to form NbS6 octahedra that share corners with four equivalent Cu(1)S6 octahedra, edges with two equivalent Cr(2)S6 octahedra, edges with four equivalent Cr(1)S6 octahedra, and faces with two equivalent Cu(2)S6 octahedra. The corner-sharing octahedral tilt angles are 50°. Both Nb(1)-S(2) bond lengths are 2.47 Å. All Nb(1)-S(3) bond lengths are 2.50 Å. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to two equivalent S(1), two equivalent S(2), and two equivalent S(3) atoms to form CrS6 octahedra that share corners with four equivalent Cu(1)S6 octahedra, corners with four equivalent Cu(2)S6 octahedra, edges with two equivalent Nb(1)S6 octahedra, edges with two equivalent Cr(1)S6 octahedra, and edges with two equivalent Cr(2)S6 octahedra. The corner-sharing octahedral tilt angles range from 44-49°. Both Cr(1)-S(1) bond lengths are 2.38 Å. Both Cr(1)-S(2) bond lengths are 2.42 Å. Both Cr(1)-S(3) bond lengths are 2.44 Å. In the second Cr site, Cr(2) is bonded to two equivalent S(1) and four equivalent S(3) atoms to form CrS6 octahedra that share corners with four equivalent Cu(2)S6 octahedra, edges with two equivalent Nb(1)S6 octahedra, edges with four equivalent Cr(1)S6 octahedra, and faces with two equivalent Cu(1)S6 octahedra. The corner-sharing octahedral tilt angles are 50°. Both Cr(2)-S(1) bond lengths are 2.36 Å. All Cr(2)-S(3) bond lengths are 2.43 Å. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to two equivalent S(1) and four equivalent S(3) atoms to form CuS6 octahedra that share corners with four equivalent Nb(1)S6 octahedra, corners with eight equivalent Cr(1)S6 octahedra, edges with two equivalent Cu(2)S6 octahedra, and faces with two equivalent Cr(2)S6 octahedra. The corner-sharing octahedral tilt angles range from 44-50°. Both Cu(1)-S(1) bond lengths are 2.46 Å. All Cu(1)-S(3) bond lengths are 2.52 Å. In the second Cu site, Cu(2) is bonded to two equivalent S(2) and four equivalent S(3) atoms to form CuS6 octahedra that share corners with four equivalent Cr(2)S6 octahedra, corners with eight equivalent Cr(1)S6 octahedra, edges with two equivalent Cu(1)S6 octahedra, and faces with two equivalent Nb(1)S6 octahedra. The corner-sharing octahedral tilt angles range from 47-50°. Both Cu(2)-S(2) bond lengths are 2.43 Å. All Cu(2)-S(3) bond lengths are 2.59 Å. There are three inequivalent S sites. In the first S site, S(1) is bonded in a rectangular see-saw-like geometry to one Cr(2), two equivalent Cr(1), and one Cu(1) atom. In the second S site, S(2) is bonded in a rectangular see-saw-like geometry to one Nb(1), two equivalent Cr(1), and one Cu(2) atom. In the third S site, S(3) is bonded to one Nb(1), one Cr(1), one Cr(2), one Cu(1), and one Cu(2) atom to form a mixture of distorted corner and edge-sharing SNbCr2Cu2 square pyramids.