NbCr3(CuS4)2 crystallizes in the orthorhombic Pmc2_1 space group. Nb(1) is bonded to one S(3), one S(8), two equivalent S(1), and two equivalent S(6) atoms to form distorted NbS6 octahedra that share  a cornercorner with one Cr(1)S6 octahedra, corners with two equivalent Cr(2)S6 octahedra, edges with two equivalent Nb(1)S6 octahedra, and edges with two equivalent Cr(2)S6 octahedra. The corner-sharing octahedral tilt angles range from 54-57°. There are three inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to one S(3), one S(5), two equivalent S(4), and two equivalent S(7) atoms to form CrS6 octahedra that share  a cornercorner with one Nb(1)S6 octahedra, corners with two equivalent Cr(3)S6 octahedra, edges with two equivalent Cr(1)S6 octahedra, edges with two equivalent Cr(2)S6 octahedra, and edges with two equivalent Cr(3)S6 octahedra. The corner-sharing octahedral tilt angles range from 57-58°. In the second Cr site, Cr(2) is bonded to one S(4), one S(6), two equivalent S(3), and two equivalent S(8) atoms to form CrS6 octahedra that share  a cornercorner with one Cr(3)S6 octahedra, corners with two equivalent Nb(1)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 54-57°. In the third Cr site, Cr(3) is bonded to one S(4), one S(7), two equivalent S(2), and two equivalent S(5) atoms to form a mixture of corner and edge-sharing CrS6 octahedra. The corner-sharing octahedral tilt angles range from 57-58°. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a 7-coordinate geometry to one S(1), two equivalent S(2), two equivalent S(5), and two equivalent S(8) atoms. In the second Cu site, Cu(2) is bonded in a 7-coordinate geometry to one S(2), two equivalent S(1), two equivalent S(6), and two equivalent S(7) atoms. There are eight inequivalent S sites. In the first S site, S(1) is bonded to two equivalent Nb(1), one Cu(1), and two equivalent Cu(2) atoms to form SNb2Cu3 square pyramids that share corners with two equivalent S(7)Cr3Cu2 square pyramids, corners with two equivalent S(5)Cr3Cu2 trigonal bipyramids,  an edgeedge with one S(7)Cr3Cu2 square pyramid, edges with two equivalent S(2)Cr2Cu3 square pyramids, edges with two equivalent S(1)Nb2Cu3 square pyramids, and edges with two equivalent S(8)NbCr2Cu2 square pyramids. In the second S site, S(2) is bonded to two equivalent Cr(3), one Cu(2), and two equivalent Cu(1) atoms to form SCr2Cu3 square pyramids that share corners with two equivalent S(8)NbCr2Cu2 square pyramids, corners with four equivalent S(5)Cr3Cu2 trigonal bipyramids,  an edgeedge with one S(8)NbCr2Cu2 square pyramid, edges with two equivalent S(2)Cr2Cu3 square pyramids, edges with two equivalent S(7)Cr3Cu2 square pyramids, edges with two equivalent S(1)Nb2Cu3 square pyramids, and edges with two equivalent S(5)Cr3Cu2 trigonal bipyramids. In the third S site, S(3) is bonded in a rectangular see-saw-like geometry to one Nb(1), one Cr(1), and two equivalent Cr(2) atoms. In the fourth S site, S(4) is bonded in a rectangular see-saw-like geometry to one Cr(2), one Cr(3), and two equivalent Cr(1) atoms. In the fifth S site, S(5) is bonded to one Cr(1), two equivalent Cr(3), and two equivalent Cu(1) atoms to form distorted SCr3Cu2 trigonal bipyramids that share corners with two equivalent S(1)Nb2Cu3 square pyramids, corners with two equivalent S(8)NbCr2Cu2 square pyramids, corners with four equivalent S(2)Cr2Cu3 square pyramids,  an edgeedge with one S(8)NbCr2Cu2 square pyramid, edges with two equivalent S(2)Cr2Cu3 square pyramids, edges with two equivalent S(7)Cr3Cu2 square pyramids, and edges with two equivalent S(5)Cr3Cu2 trigonal bipyramids. In the sixth S site, S(6) is bonded in a 3-coordinate geometry to two equivalent Nb(1), one Cr(2), and two equivalent Cu(2) atoms. In the seventh S site, S(7) is bonded to one Cr(3), two equivalent Cr(1), and two equivalent Cu(2) atoms to form SCr3Cu2 square pyramids that share corners with two equivalent S(1)Nb2Cu3 square pyramids,  an edgeedge with one S(1)Nb2Cu3 square pyramid, edges with two equivalent S(2)Cr2Cu3 square pyramids, edges with two equivalent S(7)Cr3Cu2 square pyramids, and edges with two equivalent S(5)Cr3Cu2 trigonal bipyramids. In the eighth S site, S(8) is bonded to one Nb(1), two equivalent Cr(2), and two equivalent Cu(1) atoms to form SNbCr2Cu2 square pyramids that share corners with two equivalent S(2)Cr2Cu3 square pyramids, corners with two equivalent S(5)Cr3Cu2 trigonal bipyramids,  an edgeedge with one S(2)Cr2Cu3 square pyramid, edges with two equivalent S(1)Nb2Cu3 square pyramids, edges with two equivalent S(8)NbCr2Cu2 square pyramids, and  an edgeedge with one S(5)Cr3Cu2 trigonal bipyramid.
NbCr3(CuS4)2 crystallizes in the orthorhombic Pmc2_1 space group. Nb(1) is bonded to one S(3), one S(8), two equivalent S(1), and two equivalent S(6) atoms to form distorted NbS6 octahedra that share  a cornercorner with one Cr(1)S6 octahedra, corners with two equivalent Cr(2)S6 octahedra, edges with two equivalent Nb(1)S6 octahedra, and edges with two equivalent Cr(2)S6 octahedra. The corner-sharing octahedral tilt angles range from 54-57°. The Nb(1)-S(3) bond length is 2.46 Å. The Nb(1)-S(8) bond length is 2.60 Å. Both Nb(1)-S(1) bond lengths are 2.48 Å. Both Nb(1)-S(6) bond lengths are 2.47 Å. There are three inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to one S(3), one S(5), two equivalent S(4), and two equivalent S(7) atoms to form CrS6 octahedra that share  a cornercorner with one Nb(1)S6 octahedra, corners with two equivalent Cr(3)S6 octahedra, edges with two equivalent Cr(1)S6 octahedra, edges with two equivalent Cr(2)S6 octahedra, and edges with two equivalent Cr(3)S6 octahedra. The corner-sharing octahedral tilt angles range from 57-58°. The Cr(1)-S(3) bond length is 2.56 Å. The Cr(1)-S(5) bond length is 2.37 Å. Both Cr(1)-S(4) bond lengths are 2.40 Å. Both Cr(1)-S(7) bond lengths are 2.39 Å. In the second Cr site, Cr(2) is bonded to one S(4), one S(6), two equivalent S(3), and two equivalent S(8) atoms to form CrS6 octahedra that share  a cornercorner with one Cr(3)S6 octahedra, corners with two equivalent Nb(1)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 54-57°. The Cr(2)-S(4) bond length is 2.42 Å. The Cr(2)-S(6) bond length is 2.49 Å. Both Cr(2)-S(3) bond lengths are 2.44 Å. Both Cr(2)-S(8) bond lengths are 2.36 Å. In the third Cr site, Cr(3) is bonded to one S(4), one S(7), two equivalent S(2), and two equivalent S(5) atoms to form a mixture of corner and edge-sharing CrS6 octahedra. The corner-sharing octahedral tilt angles range from 57-58°. The Cr(3)-S(4) bond length is 2.51 Å. The Cr(3)-S(7) bond length is 2.41 Å. Both Cr(3)-S(2) bond lengths are 2.42 Å. Both Cr(3)-S(5) bond lengths are 2.38 Å. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a 7-coordinate geometry to one S(1), two equivalent S(2), two equivalent S(5), and two equivalent S(8) atoms. The Cu(1)-S(1) bond length is 2.58 Å. Both Cu(1)-S(2) bond lengths are 2.41 Å. Both Cu(1)-S(5) bond lengths are 2.85 Å. Both Cu(1)-S(8) bond lengths are 2.62 Å. In the second Cu site, Cu(2) is bonded in a 7-coordinate geometry to one S(2), two equivalent S(1), two equivalent S(6), and two equivalent S(7) atoms. The Cu(2)-S(2) bond length is 2.35 Å. Both Cu(2)-S(1) bond lengths are 2.57 Å. Both Cu(2)-S(6) bond lengths are 3.01 Å. Both Cu(2)-S(7) bond lengths are 2.46 Å. There are eight inequivalent S sites. In the first S site, S(1) is bonded to two equivalent Nb(1), one Cu(1), and two equivalent Cu(2) atoms to form SNb2Cu3 square pyramids that share corners with two equivalent S(7)Cr3Cu2 square pyramids, corners with two equivalent S(5)Cr3Cu2 trigonal bipyramids,  an edgeedge with one S(7)Cr3Cu2 square pyramid, edges with two equivalent S(2)Cr2Cu3 square pyramids, edges with two equivalent S(1)Nb2Cu3 square pyramids, and edges with two equivalent S(8)NbCr2Cu2 square pyramids. In the second S site, S(2) is bonded to two equivalent Cr(3), one Cu(2), and two equivalent Cu(1) atoms to form SCr2Cu3 square pyramids that share corners with two equivalent S(8)NbCr2Cu2 square pyramids, corners with four equivalent S(5)Cr3Cu2 trigonal bipyramids,  an edgeedge with one S(8)NbCr2Cu2 square pyramid, edges with two equivalent S(2)Cr2Cu3 square pyramids, edges with two equivalent S(7)Cr3Cu2 square pyramids, edges with two equivalent S(1)Nb2Cu3 square pyramids, and edges with two equivalent S(5)Cr3Cu2 trigonal bipyramids. In the third S site, S(3) is bonded in a rectangular see-saw-like geometry to one Nb(1), one Cr(1), and two equivalent Cr(2) atoms. In the fourth S site, S(4) is bonded in a rectangular see-saw-like geometry to one Cr(2), one Cr(3), and two equivalent Cr(1) atoms. In the fifth S site, S(5) is bonded to one Cr(1), two equivalent Cr(3), and two equivalent Cu(1) atoms to form distorted SCr3Cu2 trigonal bipyramids that share corners with two equivalent S(1)Nb2Cu3 square pyramids, corners with two equivalent S(8)NbCr2Cu2 square pyramids, corners with four equivalent S(2)Cr2Cu3 square pyramids,  an edgeedge with one S(8)NbCr2Cu2 square pyramid, edges with two equivalent S(2)Cr2Cu3 square pyramids, edges with two equivalent S(7)Cr3Cu2 square pyramids, and edges with two equivalent S(5)Cr3Cu2 trigonal bipyramids. In the sixth S site, S(6) is bonded in a 3-coordinate geometry to two equivalent Nb(1), one Cr(2), and two equivalent Cu(2) atoms. In the seventh S site, S(7) is bonded to one Cr(3), two equivalent Cr(1), and two equivalent Cu(2) atoms to form SCr3Cu2 square pyramids that share corners with two equivalent S(1)Nb2Cu3 square pyramids,  an edgeedge with one S(1)Nb2Cu3 square pyramid, edges with two equivalent S(2)Cr2Cu3 square pyramids, edges with two equivalent S(7)Cr3Cu2 square pyramids, and edges with two equivalent S(5)Cr3Cu2 trigonal bipyramids. In the eighth S site, S(8) is bonded to one Nb(1), two equivalent Cr(2), and two equivalent Cu(1) atoms to form SNbCr2Cu2 square pyramids that share corners with two equivalent S(2)Cr2Cu3 square pyramids, corners with two equivalent S(5)Cr3Cu2 trigonal bipyramids,  an edgeedge with one S(2)Cr2Cu3 square pyramid, edges with two equivalent S(1)Nb2Cu3 square pyramids, edges with two equivalent S(8)NbCr2Cu2 square pyramids, and  an edgeedge with one S(5)Cr3Cu2 trigonal bipyramid.