NbCr3(CuS4)2 is Spinel-derived structured and crystallizes in the monoclinic P2_1/c space group. Nb(1) is bonded to two equivalent S(2), two equivalent S(3), and two equivalent S(4) atoms to form NbS6 octahedra that share corners with four equivalent Cr(2)S6 octahedra, corners with two equivalent Cu(1)S4 tetrahedra, edges with two equivalent Cr(1)S6 octahedra, edges with two equivalent Cr(2)S6 octahedra, and edges with two equivalent Cu(1)S4 tetrahedra. The corner-sharing octahedral tilt angles are 46°. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to two equivalent S(1), two equivalent S(3), and two equivalent S(4) atoms to form CrS6 octahedra that share corners with four equivalent Cr(2)S6 octahedra, corners with two equivalent Cu(1)S4 tetrahedra, edges with two equivalent Nb(1)S6 octahedra, edges with two equivalent Cr(2)S6 octahedra, and edges with two equivalent Cu(1)S4 tetrahedra. The corner-sharing octahedral tilt angles range from 47-48°. In the second Cr site, Cr(2) is bonded to one S(3), one S(4), two equivalent S(1), and two equivalent S(2) atoms to form CrS6 octahedra that share corners with two equivalent Nb(1)S6 octahedra, corners with two equivalent Cr(1)S6 octahedra, corners with four equivalent Cr(2)S6 octahedra, corners with four equivalent Cu(1)S4 tetrahedra,  an edgeedge with one Nb(1)S6 octahedra,  an edgeedge with one Cr(1)S6 octahedra, and  an edgeedge with one Cu(1)S4 tetrahedra. The corner-sharing octahedral tilt angles range from 46-48°. Cu(1) is bonded to one S(1), one S(2), one S(3), and one S(4) atom to form CuS4 tetrahedra that share  a cornercorner with one Nb(1)S6 octahedra,  a cornercorner with one Cr(1)S6 octahedra, corners with four equivalent Cr(2)S6 octahedra,  an edgeedge with one Nb(1)S6 octahedra,  an edgeedge with one Cr(1)S6 octahedra, and  an edgeedge with one Cr(2)S6 octahedra. The corner-sharing octahedral tilt angles range from 54-67°. There are four inequivalent S sites. In the first S site, S(1) is bonded in a distorted rectangular see-saw-like geometry to one Cr(1), two equivalent Cr(2), and one Cu(1) atom. In the second S site, S(2) is bonded in a distorted rectangular see-saw-like geometry to one Nb(1), two equivalent Cr(2), and one Cu(1) atom. In the third S site, S(3) is bonded in a rectangular see-saw-like geometry to one Nb(1), one Cr(1), one Cr(2), and one Cu(1) atom. In the fourth S site, S(4) is bonded in a rectangular see-saw-like geometry to one Nb(1), one Cr(1), one Cr(2), and one Cu(1) atom.
NbCr3(CuS4)2 is Spinel-derived structured and crystallizes in the monoclinic P2_1/c space group. Nb(1) is bonded to two equivalent S(2), two equivalent S(3), and two equivalent S(4) atoms to form NbS6 octahedra that share corners with four equivalent Cr(2)S6 octahedra, corners with two equivalent Cu(1)S4 tetrahedra, edges with two equivalent Cr(1)S6 octahedra, edges with two equivalent Cr(2)S6 octahedra, and edges with two equivalent Cu(1)S4 tetrahedra. The corner-sharing octahedral tilt angles are 46°. Both Nb(1)-S(2) bond lengths are 2.51 Å. Both Nb(1)-S(3) bond lengths are 2.51 Å. Both Nb(1)-S(4) bond lengths are 2.44 Å. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to two equivalent S(1), two equivalent S(3), and two equivalent S(4) atoms to form CrS6 octahedra that share corners with four equivalent Cr(2)S6 octahedra, corners with two equivalent Cu(1)S4 tetrahedra, edges with two equivalent Nb(1)S6 octahedra, edges with two equivalent Cr(2)S6 octahedra, and edges with two equivalent Cu(1)S4 tetrahedra. The corner-sharing octahedral tilt angles range from 47-48°. Both Cr(1)-S(1) bond lengths are 2.44 Å. Both Cr(1)-S(3) bond lengths are 2.45 Å. Both Cr(1)-S(4) bond lengths are 2.37 Å. In the second Cr site, Cr(2) is bonded to one S(3), one S(4), two equivalent S(1), and two equivalent S(2) atoms to form CrS6 octahedra that share corners with two equivalent Nb(1)S6 octahedra, corners with two equivalent Cr(1)S6 octahedra, corners with four equivalent Cr(2)S6 octahedra, corners with four equivalent Cu(1)S4 tetrahedra,  an edgeedge with one Nb(1)S6 octahedra,  an edgeedge with one Cr(1)S6 octahedra, and  an edgeedge with one Cu(1)S4 tetrahedra. The corner-sharing octahedral tilt angles range from 46-48°. The Cr(2)-S(3) bond length is 2.41 Å. The Cr(2)-S(4) bond length is 2.39 Å. There is one shorter (2.41 Å) and one longer (2.46 Å) Cr(2)-S(1) bond length. There is one shorter (2.40 Å) and one longer (2.51 Å) Cr(2)-S(2) bond length. Cu(1) is bonded to one S(1), one S(2), one S(3), and one S(4) atom to form CuS4 tetrahedra that share  a cornercorner with one Nb(1)S6 octahedra,  a cornercorner with one Cr(1)S6 octahedra, corners with four equivalent Cr(2)S6 octahedra,  an edgeedge with one Nb(1)S6 octahedra,  an edgeedge with one Cr(1)S6 octahedra, and  an edgeedge with one Cr(2)S6 octahedra. The corner-sharing octahedral tilt angles range from 54-67°. The Cu(1)-S(1) bond length is 2.28 Å. The Cu(1)-S(2) bond length is 2.24 Å. The Cu(1)-S(3) bond length is 2.24 Å. The Cu(1)-S(4) bond length is 2.22 Å. There are four inequivalent S sites. In the first S site, S(1) is bonded in a distorted rectangular see-saw-like geometry to one Cr(1), two equivalent Cr(2), and one Cu(1) atom. In the second S site, S(2) is bonded in a distorted rectangular see-saw-like geometry to one Nb(1), two equivalent Cr(2), and one Cu(1) atom. In the third S site, S(3) is bonded in a rectangular see-saw-like geometry to one Nb(1), one Cr(1), one Cr(2), and one Cu(1) atom. In the fourth S site, S(4) is bonded in a rectangular see-saw-like geometry to one Nb(1), one Cr(1), one Cr(2), and one Cu(1) atom.