TaCr3(CuS4)2 crystallizes in the monoclinic P2/c space group. Ta(1) is bonded to two equivalent S(1), two equivalent S(3), and two equivalent S(4) atoms to form TaS6 octahedra that share edges with two equivalent Cr(2)S6 octahedra, edges with four equivalent Cr(1)S6 octahedra, and edges with two equivalent Cu(1)S6 pentagonal pyramids. There are two inequivalent Cr sites. In the first Cr site, Cr(1) 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 three equivalent Cu(1)S6 pentagonal pyramids, edges with two equivalent Ta(1)S6 octahedra, edges with two equivalent Cr(1)S6 octahedra, edges with two equivalent Cr(2)S6 octahedra, and  an edgeedge with one Cu(1)S6 pentagonal pyramid. In the second Cr site, Cr(2) is bonded to two equivalent S(2), two equivalent S(3), and two equivalent S(4) atoms to form CrS6 octahedra that share edges with two equivalent Ta(1)S6 octahedra, edges with four equivalent Cr(1)S6 octahedra, and edges with two equivalent Cu(1)S6 pentagonal pyramids. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to two equivalent S(1), two equivalent S(2), and two equivalent S(3) atoms to form distorted CuS6 pentagonal pyramids that share corners with six equivalent Cr(1)S6 octahedra, edges with two equivalent Ta(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 4-8°. In the second Cu site, Cu(2) is bonded in a 6-coordinate geometry to two equivalent S(1), two equivalent S(2), and two equivalent S(4) atoms. There are four inequivalent S sites. In the first S site, S(1) is bonded to one Ta(1), two equivalent Cr(1), one Cu(1), and one Cu(2) atom to form STaCr2Cu2 trigonal bipyramids that share corners with two equivalent S(2)Cr3Cu2 trigonal bipyramids, corners with three equivalent S(1)TaCr2Cu2 trigonal bipyramids,  an edgeedge with one S(1)TaCr2Cu2 trigonal bipyramid, and edges with three equivalent S(2)Cr3Cu2 trigonal bipyramids. In the second S site, S(2) is bonded to one Cr(2), two equivalent Cr(1), one Cu(1), and one Cu(2) atom to form distorted SCr3Cu2 trigonal bipyramids that share corners with two equivalent S(1)TaCr2Cu2 trigonal bipyramids, corners with three equivalent S(2)Cr3Cu2 trigonal bipyramids,  an edgeedge with one S(2)Cr3Cu2 trigonal bipyramid, and edges with three equivalent S(1)TaCr2Cu2 trigonal bipyramids. In the third S site, S(3) is bonded in a rectangular see-saw-like geometry to one Ta(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 Ta(1), one Cr(1), one Cr(2), and one Cu(2) atom.
TaCr3(CuS4)2 crystallizes in the monoclinic P2/c space group. Ta(1) is bonded to two equivalent S(1), two equivalent S(3), and two equivalent S(4) atoms to form TaS6 octahedra that share edges with two equivalent Cr(2)S6 octahedra, edges with four equivalent Cr(1)S6 octahedra, and edges with two equivalent Cu(1)S6 pentagonal pyramids. Both Ta(1)-S(1) bond lengths are 2.48 Å. Both Ta(1)-S(3) bond lengths are 2.45 Å. Both Ta(1)-S(4) bond lengths are 2.45 Å. There are two inequivalent Cr sites. In the first Cr site, Cr(1) 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 three equivalent Cu(1)S6 pentagonal pyramids, edges with two equivalent Ta(1)S6 octahedra, edges with two equivalent Cr(1)S6 octahedra, edges with two equivalent Cr(2)S6 octahedra, and  an edgeedge with one Cu(1)S6 pentagonal pyramid. The Cr(1)-S(3) bond length is 2.42 Å. The Cr(1)-S(4) bond length is 2.41 Å. There is one shorter (2.40 Å) and one longer (2.44 Å) Cr(1)-S(1) bond length. There is one shorter (2.38 Å) and one longer (2.46 Å) Cr(1)-S(2) bond length. In the second Cr site, Cr(2) is bonded to two equivalent S(2), two equivalent S(3), and two equivalent S(4) atoms to form CrS6 octahedra that share edges with two equivalent Ta(1)S6 octahedra, edges with four equivalent Cr(1)S6 octahedra, and edges with two equivalent Cu(1)S6 pentagonal pyramids. Both Cr(2)-S(2) bond lengths are 2.40 Å. Both Cr(2)-S(3) bond lengths are 2.37 Å. Both Cr(2)-S(4) bond lengths are 2.41 Å. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to two equivalent S(1), two equivalent S(2), and two equivalent S(3) atoms to form distorted CuS6 pentagonal pyramids that share corners with six equivalent Cr(1)S6 octahedra, edges with two equivalent Ta(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 4-8°. Both Cu(1)-S(1) bond lengths are 2.66 Å. Both Cu(1)-S(2) bond lengths are 2.60 Å. Both Cu(1)-S(3) bond lengths are 2.48 Å. In the second Cu site, Cu(2) is bonded in a 6-coordinate geometry to two equivalent S(1), two equivalent S(2), and two equivalent S(4) atoms. Both Cu(2)-S(1) bond lengths are 2.60 Å. Both Cu(2)-S(2) bond lengths are 2.74 Å. Both Cu(2)-S(4) bond lengths are 2.44 Å. There are four inequivalent S sites. In the first S site, S(1) is bonded to one Ta(1), two equivalent Cr(1), one Cu(1), and one Cu(2) atom to form STaCr2Cu2 trigonal bipyramids that share corners with two equivalent S(2)Cr3Cu2 trigonal bipyramids, corners with three equivalent S(1)TaCr2Cu2 trigonal bipyramids,  an edgeedge with one S(1)TaCr2Cu2 trigonal bipyramid, and edges with three equivalent S(2)Cr3Cu2 trigonal bipyramids. In the second S site, S(2) is bonded to one Cr(2), two equivalent Cr(1), one Cu(1), and one Cu(2) atom to form distorted SCr3Cu2 trigonal bipyramids that share corners with two equivalent S(1)TaCr2Cu2 trigonal bipyramids, corners with three equivalent S(2)Cr3Cu2 trigonal bipyramids,  an edgeedge with one S(2)Cr3Cu2 trigonal bipyramid, and edges with three equivalent S(1)TaCr2Cu2 trigonal bipyramids. In the third S site, S(3) is bonded in a rectangular see-saw-like geometry to one Ta(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 Ta(1), one Cr(1), one Cr(2), and one Cu(2) atom.