HfCrCuS4 crystallizes in the monoclinic P2 space group. There are two inequivalent Hf sites. In the first Hf site, Hf(1) is bonded to two equivalent S(1), two equivalent S(2), and two equivalent S(3) atoms to form HfS6 octahedra that share corners with four equivalent Cu(1)S6 octahedra, corners with four equivalent Cu(2)S6 octahedra, edges with two equivalent Hf(2)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 47-50°. In the second Hf site, Hf(2) is bonded to two equivalent S(2), two equivalent S(3), and two equivalent S(4) atoms to form HfS6 octahedra that share corners with four equivalent Cu(1)S6 octahedra, edges with two equivalent Hf(1)S6 octahedra, edges with two equivalent Cr(1)S6 octahedra, edges with two equivalent Cr(2)S6 octahedra, and faces with two equivalent Cu(2)S6 octahedra. The corner-sharing octahedral tilt angles range from 47-53°. 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(4) 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 Hf(1)S6 octahedra, edges with two equivalent Hf(2)S6 octahedra, and edges with two equivalent Cr(2)S6 octahedra. The corner-sharing octahedral tilt angles range from 41-48°. In the second Cr site, Cr(2) 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 Cu(2)S6 octahedra, edges with two equivalent Hf(1)S6 octahedra, edges with two equivalent Hf(2)S6 octahedra, edges with two equivalent Cr(1)S6 octahedra, and faces with two equivalent Cu(1)S6 octahedra. The corner-sharing octahedral tilt angles range from 48-52°. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to two equivalent S(1), two equivalent S(3), and two equivalent S(4) atoms to form CuS6 octahedra that share corners with four equivalent Hf(1)S6 octahedra, corners with four equivalent Hf(2)S6 octahedra, corners with four 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 41-53°. In the second Cu site, Cu(2) is bonded to two equivalent S(2), two equivalent S(3), and two equivalent S(4) atoms to form distorted CuS6 octahedra that share corners with four equivalent Hf(1)S6 octahedra, corners with four equivalent Cr(1)S6 octahedra, corners with four equivalent Cr(2)S6 octahedra, edges with two equivalent Cu(1)S6 octahedra, and faces with two equivalent Hf(2)S6 octahedra. The corner-sharing octahedral tilt angles range from 47-52°. There are four inequivalent S sites. In the first S site, S(1) is bonded in a rectangular see-saw-like geometry to one Hf(1), one Cr(1), one Cr(2), and one Cu(1) atom. In the second S site, S(2) is bonded in a rectangular see-saw-like geometry to one Hf(1), one Hf(2), one Cr(1), and one Cu(2) atom. In the third S site, S(3) is bonded to one Hf(1), one Hf(2), one Cr(2), one Cu(1), and one Cu(2) atom to form distorted SHf2CrCu2 square pyramids that share  a cornercorner with one S(3)Hf2CrCu2 square pyramid, corners with four equivalent S(4)HfCr2Cu2 square pyramids, edges with two equivalent S(3)Hf2CrCu2 square pyramids, and edges with two equivalent S(4)HfCr2Cu2 square pyramids. In the fourth S site, S(4) is bonded to one Hf(2), one Cr(1), one Cr(2), one Cu(1), and one Cu(2) atom to form distorted SHfCr2Cu2 square pyramids that share  a cornercorner with one S(4)HfCr2Cu2 square pyramid, corners with four equivalent S(3)Hf2CrCu2 square pyramids, edges with two equivalent S(3)Hf2CrCu2 square pyramids, and edges with two equivalent S(4)HfCr2Cu2 square pyramids.
HfCrCuS4 crystallizes in the monoclinic P2 space group. There are two inequivalent Hf sites. In the first Hf site, Hf(1) is bonded to two equivalent S(1), two equivalent S(2), and two equivalent S(3) atoms to form HfS6 octahedra that share corners with four equivalent Cu(1)S6 octahedra, corners with four equivalent Cu(2)S6 octahedra, edges with two equivalent Hf(2)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 47-50°. Both Hf(1)-S(1) bond lengths are 2.50 Å. Both Hf(1)-S(2) bond lengths are 2.58 Å. Both Hf(1)-S(3) bond lengths are 2.55 Å. In the second Hf site, Hf(2) is bonded to two equivalent S(2), two equivalent S(3), and two equivalent S(4) atoms to form HfS6 octahedra that share corners with four equivalent Cu(1)S6 octahedra, edges with two equivalent Hf(1)S6 octahedra, edges with two equivalent Cr(1)S6 octahedra, edges with two equivalent Cr(2)S6 octahedra, and faces with two equivalent Cu(2)S6 octahedra. The corner-sharing octahedral tilt angles range from 47-53°. Both Hf(2)-S(2) bond lengths are 2.53 Å. Both Hf(2)-S(3) bond lengths are 2.60 Å. Both Hf(2)-S(4) bond lengths are 2.51 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(4) 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 Hf(1)S6 octahedra, edges with two equivalent Hf(2)S6 octahedra, and edges with two equivalent Cr(2)S6 octahedra. The corner-sharing octahedral tilt angles range from 41-48°. Both Cr(1)-S(1) bond lengths are 2.43 Å. Both Cr(1)-S(2) bond lengths are 2.45 Å. Both Cr(1)-S(4) bond lengths are 2.45 Å. In the second Cr site, Cr(2) 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 Cu(2)S6 octahedra, edges with two equivalent Hf(1)S6 octahedra, edges with two equivalent Hf(2)S6 octahedra, edges with two equivalent Cr(1)S6 octahedra, and faces with two equivalent Cu(1)S6 octahedra. The corner-sharing octahedral tilt angles range from 48-52°. Both Cr(2)-S(1) bond lengths are 2.41 Å. Both Cr(2)-S(3) bond lengths are 2.46 Å. Both Cr(2)-S(4) bond lengths are 2.46 Å. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to two equivalent S(1), two equivalent S(3), and two equivalent S(4) atoms to form CuS6 octahedra that share corners with four equivalent Hf(1)S6 octahedra, corners with four equivalent Hf(2)S6 octahedra, corners with four 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 41-53°. Both Cu(1)-S(1) bond lengths are 2.43 Å. Both Cu(1)-S(3) bond lengths are 2.55 Å. Both Cu(1)-S(4) bond lengths are 2.53 Å. In the second Cu site, Cu(2) is bonded to two equivalent S(2), two equivalent S(3), and two equivalent S(4) atoms to form distorted CuS6 octahedra that share corners with four equivalent Hf(1)S6 octahedra, corners with four equivalent Cr(1)S6 octahedra, corners with four equivalent Cr(2)S6 octahedra, edges with two equivalent Cu(1)S6 octahedra, and faces with two equivalent Hf(2)S6 octahedra. The corner-sharing octahedral tilt angles range from 47-52°. Both Cu(2)-S(2) bond lengths are 2.46 Å. Both Cu(2)-S(3) bond lengths are 2.60 Å. Both Cu(2)-S(4) bond lengths are 2.65 Å. There are four inequivalent S sites. In the first S site, S(1) is bonded in a rectangular see-saw-like geometry to one Hf(1), one Cr(1), one Cr(2), and one Cu(1) atom. In the second S site, S(2) is bonded in a rectangular see-saw-like geometry to one Hf(1), one Hf(2), one Cr(1), and one Cu(2) atom. In the third S site, S(3) is bonded to one Hf(1), one Hf(2), one Cr(2), one Cu(1), and one Cu(2) atom to form distorted SHf2CrCu2 square pyramids that share  a cornercorner with one S(3)Hf2CrCu2 square pyramid, corners with four equivalent S(4)HfCr2Cu2 square pyramids, edges with two equivalent S(3)Hf2CrCu2 square pyramids, and edges with two equivalent S(4)HfCr2Cu2 square pyramids. In the fourth S site, S(4) is bonded to one Hf(2), one Cr(1), one Cr(2), one Cu(1), and one Cu(2) atom to form distorted SHfCr2Cu2 square pyramids that share  a cornercorner with one S(4)HfCr2Cu2 square pyramid, corners with four equivalent S(3)Hf2CrCu2 square pyramids, edges with two equivalent S(3)Hf2CrCu2 square pyramids, and edges with two equivalent S(4)HfCr2Cu2 square pyramids.