MgV4(CuS4)2 crystallizes in the trigonal R-3m space group. Mg(1) is bonded in a 8-coordinate geometry to two equivalent Cu(1) and six equivalent S(1) atoms. There are two inequivalent V sites. In the first V site, V(1) is bonded to two equivalent S(2) and four equivalent S(1) atoms to form edge-sharing VS6 octahedra. In the second V site, V(2) is bonded to six equivalent S(1) atoms to form edge-sharing VS6 octahedra. Cu(1) is bonded in a 5-coordinate geometry to one Mg(1), one S(2), and three equivalent S(1) atoms. There are two inequivalent S sites. In the first S site, S(1) is bonded to one Mg(1), one V(2), two equivalent V(1), and one Cu(1) atom to form a mixture of corner and edge-sharing SMgV3Cu square pyramids. In the second S site, S(2) is bonded in a rectangular see-saw-like geometry to three equivalent V(1) and one Cu(1) atom.
MgV4(CuS4)2 crystallizes in the trigonal R-3m space group. Mg(1) is bonded in a 8-coordinate geometry to two equivalent Cu(1) and six equivalent S(1) atoms. Both Mg(1)-Cu(1) bond lengths are 2.58 Å. All Mg(1)-S(1) bond lengths are 2.59 Å. There are two inequivalent V sites. In the first V site, V(1) is bonded to two equivalent S(2) and four equivalent S(1) atoms to form edge-sharing VS6 octahedra. Both V(1)-S(2) bond lengths are 2.41 Å. All V(1)-S(1) bond lengths are 2.47 Å. In the second V site, V(2) is bonded to six equivalent S(1) atoms to form edge-sharing VS6 octahedra. All V(2)-S(1) bond lengths are 2.46 Å. Cu(1) is bonded in a 5-coordinate geometry to one Mg(1), one S(2), and three equivalent S(1) atoms. The Cu(1)-S(2) bond length is 2.21 Å. All Cu(1)-S(1) bond lengths are 2.36 Å. There are two inequivalent S sites. In the first S site, S(1) is bonded to one Mg(1), one V(2), two equivalent V(1), and one Cu(1) atom to form a mixture of corner and edge-sharing SMgV3Cu square pyramids. In the second S site, S(2) is bonded in a rectangular see-saw-like geometry to three equivalent V(1) and one Cu(1) atom.