CuCr2S4 crystallizes in the orthorhombic Pnma space group. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to one S(3), two equivalent S(4), and three equivalent S(2) atoms to form CrS6 octahedra that share corners with three equivalent Cr(2)S6 octahedra, corners with four equivalent Cu(1)S7 pentagonal bipyramids, edges with two equivalent Cr(2)S6 octahedra, edges with four equivalent Cr(1)S6 octahedra, and  an edgeedge with one Cu(1)S7 pentagonal bipyramid. The corner-sharing octahedral tilt angles range from 52-59°. In the second Cr site, Cr(2) is bonded to one S(2), one S(4), two equivalent S(1), and two equivalent S(3) atoms to form CrS6 octahedra that share corners with three equivalent Cr(1)S6 octahedra, corners with four equivalent Cu(1)S7 pentagonal bipyramids, edges with two equivalent Cr(1)S6 octahedra, edges with two equivalent Cr(2)S6 octahedra, and edges with four equivalent Cu(1)S7 pentagonal bipyramids. The corner-sharing octahedral tilt angles range from 52-59°. Cu(1) is bonded to two equivalent S(3), two equivalent S(4), and three equivalent S(1) atoms to form distorted CuS7 pentagonal bipyramids that share corners with four equivalent Cr(1)S6 octahedra, corners with four equivalent Cr(2)S6 octahedra,  an edgeedge with one Cr(1)S6 octahedra, edges with four equivalent Cr(2)S6 octahedra, edges with two equivalent Cu(1)S7 pentagonal bipyramids, and faces with two equivalent Cu(1)S7 pentagonal bipyramids. The corner-sharing octahedral tilt angles range from 15-64°. There are four inequivalent S sites. In the first S site, S(1) is bonded to two equivalent Cr(2) and three equivalent Cu(1) atoms to form SCr2Cu3 square pyramids that share corners with two equivalent S(4)Cr3Cu2 square pyramids, corners with six equivalent S(3)Cr3Cu2 trigonal bipyramids, edges with three equivalent S(4)Cr3Cu2 square pyramids, edges with four equivalent S(1)Cr2Cu3 square pyramids, and edges with two equivalent S(3)Cr3Cu2 trigonal bipyramids. In the second S site, S(2) is bonded in a rectangular see-saw-like geometry to one Cr(2) and three equivalent Cr(1) atoms. In the third S site, S(3) is bonded to one Cr(1), two equivalent Cr(2), and two equivalent Cu(1) atoms to form distorted SCr3Cu2 trigonal bipyramids that share corners with two equivalent S(4)Cr3Cu2 square pyramids, corners with six equivalent S(1)Cr2Cu3 square pyramids, edges with two equivalent S(1)Cr2Cu3 square pyramids, edges with three equivalent S(4)Cr3Cu2 square pyramids, and edges with two equivalent S(3)Cr3Cu2 trigonal bipyramids. In the fourth S site, S(4) is bonded to one Cr(2), two equivalent Cr(1), and two equivalent Cu(1) atoms to form SCr3Cu2 square pyramids that share corners with two equivalent S(1)Cr2Cu3 square pyramids, corners with two equivalent S(3)Cr3Cu2 trigonal bipyramids, edges with two equivalent S(4)Cr3Cu2 square pyramids, edges with three equivalent S(1)Cr2Cu3 square pyramids, and edges with three equivalent S(3)Cr3Cu2 trigonal bipyramids.
CuCr2S4 crystallizes in the orthorhombic Pnma space group. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to one S(3), two equivalent S(4), and three equivalent S(2) atoms to form CrS6 octahedra that share corners with three equivalent Cr(2)S6 octahedra, corners with four equivalent Cu(1)S7 pentagonal bipyramids, edges with two equivalent Cr(2)S6 octahedra, edges with four equivalent Cr(1)S6 octahedra, and  an edgeedge with one Cu(1)S7 pentagonal bipyramid. The corner-sharing octahedral tilt angles range from 52-59°. The Cr(1)-S(3) bond length is 2.37 Å. Both Cr(1)-S(4) bond lengths are 2.38 Å. There are two shorter (2.38 Å) and one longer (2.50 Å) Cr(1)-S(2) bond length. In the second Cr site, Cr(2) is bonded to one S(2), one S(4), two equivalent S(1), and two equivalent S(3) atoms to form CrS6 octahedra that share corners with three equivalent Cr(1)S6 octahedra, corners with four equivalent Cu(1)S7 pentagonal bipyramids, edges with two equivalent Cr(1)S6 octahedra, edges with two equivalent Cr(2)S6 octahedra, and edges with four equivalent Cu(1)S7 pentagonal bipyramids. The corner-sharing octahedral tilt angles range from 52-59°. The Cr(2)-S(2) bond length is 2.43 Å. The Cr(2)-S(4) bond length is 2.41 Å. Both Cr(2)-S(1) bond lengths are 2.38 Å. Both Cr(2)-S(3) bond lengths are 2.41 Å. Cu(1) is bonded to two equivalent S(3), two equivalent S(4), and three equivalent S(1) atoms to form distorted CuS7 pentagonal bipyramids that share corners with four equivalent Cr(1)S6 octahedra, corners with four equivalent Cr(2)S6 octahedra,  an edgeedge with one Cr(1)S6 octahedra, edges with four equivalent Cr(2)S6 octahedra, edges with two equivalent Cu(1)S7 pentagonal bipyramids, and faces with two equivalent Cu(1)S7 pentagonal bipyramids. The corner-sharing octahedral tilt angles range from 15-64°. Both Cu(1)-S(3) bond lengths are 2.82 Å. Both Cu(1)-S(4) bond lengths are 2.56 Å. There is one shorter (2.48 Å) and two longer (2.51 Å) Cu(1)-S(1) bond lengths. There are four inequivalent S sites. In the first S site, S(1) is bonded to two equivalent Cr(2) and three equivalent Cu(1) atoms to form SCr2Cu3 square pyramids that share corners with two equivalent S(4)Cr3Cu2 square pyramids, corners with six equivalent S(3)Cr3Cu2 trigonal bipyramids, edges with three equivalent S(4)Cr3Cu2 square pyramids, edges with four equivalent S(1)Cr2Cu3 square pyramids, and edges with two equivalent S(3)Cr3Cu2 trigonal bipyramids. In the second S site, S(2) is bonded in a rectangular see-saw-like geometry to one Cr(2) and three equivalent Cr(1) atoms. In the third S site, S(3) is bonded to one Cr(1), two equivalent Cr(2), and two equivalent Cu(1) atoms to form distorted SCr3Cu2 trigonal bipyramids that share corners with two equivalent S(4)Cr3Cu2 square pyramids, corners with six equivalent S(1)Cr2Cu3 square pyramids, edges with two equivalent S(1)Cr2Cu3 square pyramids, edges with three equivalent S(4)Cr3Cu2 square pyramids, and edges with two equivalent S(3)Cr3Cu2 trigonal bipyramids. In the fourth S site, S(4) is bonded to one Cr(2), two equivalent Cr(1), and two equivalent Cu(1) atoms to form SCr3Cu2 square pyramids that share corners with two equivalent S(1)Cr2Cu3 square pyramids, corners with two equivalent S(3)Cr3Cu2 trigonal bipyramids, edges with two equivalent S(4)Cr3Cu2 square pyramids, edges with three equivalent S(1)Cr2Cu3 square pyramids, and edges with three equivalent S(3)Cr3Cu2 trigonal bipyramids.