Mg(CuS2)2 crystallizes in the monoclinic Pm space group. Mg(1) is bonded in a 5-coordinate geometry to one S(4), two equivalent S(1), and two equivalent S(3) atoms. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to one S(1), one S(4), and two equivalent S(2) atoms to form corner-sharing CuS4 tetrahedra. In the second Cu site, Cu(2) is bonded in a 5-coordinate geometry to one S(2), two equivalent S(1), and two equivalent S(4) atoms. There are four inequivalent S sites. In the first S site, S(1) is bonded in a 5-coordinate geometry to two equivalent Mg(1), one Cu(1), and two equivalent Cu(2) atoms. In the second S site, S(2) is bonded to one Cu(2), two equivalent Cu(1), and one S(3) atom to form distorted SCu3S tetrahedra that share corners with two equivalent S(2)Cu3S tetrahedra and corners with four equivalent S(4)MgCu3 trigonal pyramids. In the third S site, S(3) is bonded in a distorted trigonal non-coplanar geometry to two equivalent Mg(1) and one S(2) atom. In the fourth S site, S(4) is bonded to one Mg(1), one Cu(1), and two equivalent Cu(2) atoms to form distorted SMgCu3 trigonal pyramids that share corners with four equivalent S(2)Cu3S tetrahedra and corners with two equivalent S(4)MgCu3 trigonal pyramids.
Mg(CuS2)2 crystallizes in the monoclinic Pm space group. Mg(1) is bonded in a 5-coordinate geometry to one S(4), two equivalent S(1), and two equivalent S(3) atoms. The Mg(1)-S(4) bond length is 2.42 Å. There is one shorter (2.57 Å) and one longer (2.87 Å) Mg(1)-S(1) bond length. Both Mg(1)-S(3) bond lengths are 2.45 Å. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to one S(1), one S(4), and two equivalent S(2) atoms to form corner-sharing CuS4 tetrahedra. The Cu(1)-S(1) bond length is 2.32 Å. The Cu(1)-S(4) bond length is 2.29 Å. Both Cu(1)-S(2) bond lengths are 2.33 Å. In the second Cu site, Cu(2) is bonded in a 5-coordinate geometry to one S(2), two equivalent S(1), and two equivalent S(4) atoms. The Cu(2)-S(2) bond length is 2.82 Å. Both Cu(2)-S(1) bond lengths are 2.37 Å. Both Cu(2)-S(4) bond lengths are 2.37 Å. There are four inequivalent S sites. In the first S site, S(1) is bonded in a 5-coordinate geometry to two equivalent Mg(1), one Cu(1), and two equivalent Cu(2) atoms. In the second S site, S(2) is bonded to one Cu(2), two equivalent Cu(1), and one S(3) atom to form distorted SCu3S tetrahedra that share corners with two equivalent S(2)Cu3S tetrahedra and corners with four equivalent S(4)MgCu3 trigonal pyramids. The S(2)-S(3) bond length is 2.08 Å. In the third S site, S(3) is bonded in a distorted trigonal non-coplanar geometry to two equivalent Mg(1) and one S(2) atom. In the fourth S site, S(4) is bonded to one Mg(1), one Cu(1), and two equivalent Cu(2) atoms to form distorted SMgCu3 trigonal pyramids that share corners with four equivalent S(2)Cu3S tetrahedra and corners with two equivalent S(4)MgCu3 trigonal pyramids.