Cu5FeS4 crystallizes in the monoclinic Pm space group. Fe(1) is bonded to one S(1), one S(2), and two equivalent S(4) atoms to form FeS4 tetrahedra that share corners with two equivalent Fe(1)S4 tetrahedra, corners with two equivalent Cu(3)S4 tetrahedra, corners with four equivalent Cu(2)S4 tetrahedra, corners with four equivalent Cu(5)S4 tetrahedra,  an edgeedge with one Cu(1)S4 tetrahedra, and edges with two equivalent Cu(4)S4 tetrahedra. There are five inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to one S(1), one S(2), and two equivalent S(3) atoms to form CuS4 tetrahedra that share corners with two equivalent Cu(1)S4 tetrahedra, corners with four equivalent Cu(3)S4 tetrahedra, corners with four equivalent Cu(4)S4 tetrahedra,  an edgeedge with one Fe(1)S4 tetrahedra,  an edgeedge with one Cu(3)S4 tetrahedra, edges with two equivalent Cu(2)S4 tetrahedra, and edges with two equivalent Cu(5)S4 tetrahedra. In the second Cu site, Cu(2) is bonded to one S(3), one S(4), and two equivalent S(2) atoms to form distorted CuS4 tetrahedra that share corners with two equivalent Cu(2)S4 tetrahedra, corners with two equivalent Cu(5)S4 tetrahedra, corners with four equivalent Fe(1)S4 tetrahedra, corners with four equivalent Cu(3)S4 tetrahedra,  an edgeedge with one Cu(4)S4 tetrahedra, and edges with two equivalent Cu(1)S4 tetrahedra. In the third Cu site, Cu(3) is bonded to one S(1), one S(2), and two equivalent S(3) atoms to form distorted CuS4 tetrahedra that share corners with two equivalent Fe(1)S4 tetrahedra, corners with two equivalent Cu(3)S4 tetrahedra, corners with four equivalent Cu(1)S4 tetrahedra, corners with four equivalent Cu(2)S4 tetrahedra, corners with four equivalent Cu(5)S4 tetrahedra,  an edgeedge with one Cu(1)S4 tetrahedra, and edges with two equivalent Cu(4)S4 tetrahedra. In the fourth Cu site, Cu(4) is bonded to one S(3), one S(4), and two equivalent S(1) atoms to form CuS4 tetrahedra that share corners with two equivalent Cu(4)S4 tetrahedra, corners with four equivalent Cu(1)S4 tetrahedra, corners with four equivalent Cu(5)S4 tetrahedra,  an edgeedge with one Cu(2)S4 tetrahedra,  an edgeedge with one Cu(5)S4 tetrahedra, edges with two equivalent Fe(1)S4 tetrahedra, and edges with two equivalent Cu(3)S4 tetrahedra. In the fifth Cu site, Cu(5) is bonded to one S(3), one S(4), and two equivalent S(1) atoms to form CuS4 tetrahedra that share corners with two equivalent Cu(2)S4 tetrahedra, corners with two equivalent Cu(5)S4 tetrahedra, corners with four equivalent Fe(1)S4 tetrahedra, corners with four equivalent Cu(3)S4 tetrahedra, corners with four equivalent Cu(4)S4 tetrahedra,  an edgeedge with one Cu(4)S4 tetrahedra, and edges with two equivalent Cu(1)S4 tetrahedra. There are four inequivalent S sites. In the first S site, S(1) is bonded in a 7-coordinate geometry to one Fe(1), one Cu(1), one Cu(3), two equivalent Cu(4), and two equivalent Cu(5) atoms. In the second S site, S(2) is bonded to one Fe(1), one Cu(1), one Cu(3), and two equivalent Cu(2) atoms to form distorted corner-sharing SFeCu4 trigonal bipyramids. In the third S site, S(3) is bonded in a 7-coordinate geometry to one Cu(2), one Cu(4), one Cu(5), two equivalent Cu(1), and two equivalent Cu(3) atoms. In the fourth S site, S(4) is bonded in a 5-coordinate geometry to two equivalent Fe(1), one Cu(2), one Cu(4), and one Cu(5) atom.
Cu5FeS4 crystallizes in the monoclinic Pm space group. Fe(1) is bonded to one S(1), one S(2), and two equivalent S(4) atoms to form FeS4 tetrahedra that share corners with two equivalent Fe(1)S4 tetrahedra, corners with two equivalent Cu(3)S4 tetrahedra, corners with four equivalent Cu(2)S4 tetrahedra, corners with four equivalent Cu(5)S4 tetrahedra,  an edgeedge with one Cu(1)S4 tetrahedra, and edges with two equivalent Cu(4)S4 tetrahedra. The Fe(1)-S(1) bond length is 2.37 Å. The Fe(1)-S(2) bond length is 2.28 Å. Both Fe(1)-S(4) bond lengths are 2.35 Å. There are five inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to one S(1), one S(2), and two equivalent S(3) atoms to form CuS4 tetrahedra that share corners with two equivalent Cu(1)S4 tetrahedra, corners with four equivalent Cu(3)S4 tetrahedra, corners with four equivalent Cu(4)S4 tetrahedra,  an edgeedge with one Fe(1)S4 tetrahedra,  an edgeedge with one Cu(3)S4 tetrahedra, edges with two equivalent Cu(2)S4 tetrahedra, and edges with two equivalent Cu(5)S4 tetrahedra. The Cu(1)-S(1) bond length is 2.38 Å. The Cu(1)-S(2) bond length is 2.33 Å. Both Cu(1)-S(3) bond lengths are 2.36 Å. In the second Cu site, Cu(2) is bonded to one S(3), one S(4), and two equivalent S(2) atoms to form distorted CuS4 tetrahedra that share corners with two equivalent Cu(2)S4 tetrahedra, corners with two equivalent Cu(5)S4 tetrahedra, corners with four equivalent Fe(1)S4 tetrahedra, corners with four equivalent Cu(3)S4 tetrahedra,  an edgeedge with one Cu(4)S4 tetrahedra, and edges with two equivalent Cu(1)S4 tetrahedra. The Cu(2)-S(3) bond length is 2.55 Å. The Cu(2)-S(4) bond length is 2.31 Å. Both Cu(2)-S(2) bond lengths are 2.31 Å. In the third Cu site, Cu(3) is bonded to one S(1), one S(2), and two equivalent S(3) atoms to form distorted CuS4 tetrahedra that share corners with two equivalent Fe(1)S4 tetrahedra, corners with two equivalent Cu(3)S4 tetrahedra, corners with four equivalent Cu(1)S4 tetrahedra, corners with four equivalent Cu(2)S4 tetrahedra, corners with four equivalent Cu(5)S4 tetrahedra,  an edgeedge with one Cu(1)S4 tetrahedra, and edges with two equivalent Cu(4)S4 tetrahedra. The Cu(3)-S(1) bond length is 2.48 Å. The Cu(3)-S(2) bond length is 2.24 Å. Both Cu(3)-S(3) bond lengths are 2.36 Å. In the fourth Cu site, Cu(4) is bonded to one S(3), one S(4), and two equivalent S(1) atoms to form CuS4 tetrahedra that share corners with two equivalent Cu(4)S4 tetrahedra, corners with four equivalent Cu(1)S4 tetrahedra, corners with four equivalent Cu(5)S4 tetrahedra,  an edgeedge with one Cu(2)S4 tetrahedra,  an edgeedge with one Cu(5)S4 tetrahedra, edges with two equivalent Fe(1)S4 tetrahedra, and edges with two equivalent Cu(3)S4 tetrahedra. The Cu(4)-S(3) bond length is 2.32 Å. The Cu(4)-S(4) bond length is 2.39 Å. Both Cu(4)-S(1) bond lengths are 2.35 Å. In the fifth Cu site, Cu(5) is bonded to one S(3), one S(4), and two equivalent S(1) atoms to form CuS4 tetrahedra that share corners with two equivalent Cu(2)S4 tetrahedra, corners with two equivalent Cu(5)S4 tetrahedra, corners with four equivalent Fe(1)S4 tetrahedra, corners with four equivalent Cu(3)S4 tetrahedra, corners with four equivalent Cu(4)S4 tetrahedra,  an edgeedge with one Cu(4)S4 tetrahedra, and edges with two equivalent Cu(1)S4 tetrahedra. The Cu(5)-S(3) bond length is 2.34 Å. The Cu(5)-S(4) bond length is 2.25 Å. Both Cu(5)-S(1) bond lengths are 2.43 Å. There are four inequivalent S sites. In the first S site, S(1) is bonded in a 7-coordinate geometry to one Fe(1), one Cu(1), one Cu(3), two equivalent Cu(4), and two equivalent Cu(5) atoms. In the second S site, S(2) is bonded to one Fe(1), one Cu(1), one Cu(3), and two equivalent Cu(2) atoms to form distorted corner-sharing SFeCu4 trigonal bipyramids. In the third S site, S(3) is bonded in a 7-coordinate geometry to one Cu(2), one Cu(4), one Cu(5), two equivalent Cu(1), and two equivalent Cu(3) atoms. In the fourth S site, S(4) is bonded in a 5-coordinate geometry to two equivalent Fe(1), one Cu(2), one Cu(4), and one Cu(5) atom.