Na2MgNb2(CuS2)4 crystallizes in the monoclinic Pm space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a 3-coordinate geometry to one S(1) and two equivalent S(4) atoms. In the second Na site, Na(2) is bonded in a distorted T-shaped geometry to one S(2) and two equivalent S(3) atoms. Mg(1) is bonded in a 3-coordinate geometry to one Cu(3), one S(5), and two equivalent S(3) atoms. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to one S(1), one S(6), and two equivalent S(3) atoms to form distorted NbS4 tetrahedra that share edges with two equivalent Cu(2)S4 tetrahedra. In the second Nb site, Nb(2) is bonded in a distorted tetrahedral geometry to one S(2), one S(5), and two equivalent S(4) atoms. There are three inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a 4-coordinate geometry to one S(3), one S(4), one S(5), and one S(6) atom. In the second Cu site, Cu(2) is bonded to one S(1), one S(6), and two equivalent S(3) atoms to form CuS4 tetrahedra that share edges with two equivalent Nb(1)S4 tetrahedra. In the third Cu site, Cu(3) is bonded in a 5-coordinate geometry to one Mg(1), one S(2), one S(5), and two equivalent S(4) atoms. There are six inequivalent S sites. In the first S site, S(1) is bonded in a distorted trigonal non-coplanar geometry to one Na(1), one Nb(1), and one Cu(2) atom. In the second S site, S(2) is bonded in a T-shaped geometry to one Na(2), one Nb(2), and one Cu(3) atom. In the third S site, S(3) is bonded in a distorted pentagonal planar geometry to one Na(2), one Mg(1), one Nb(1), one Cu(1), and one Cu(2) atom. In the fourth S site, S(4) is bonded in a 4-coordinate geometry to one Na(1), one Nb(2), one Cu(1), and one Cu(3) atom. In the fifth S site, S(5) is bonded in a distorted pentagonal planar geometry to one Mg(1), one Nb(2), one Cu(3), and two equivalent Cu(1) atoms. In the sixth S site, S(6) is bonded in a 4-coordinate geometry to one Nb(1), one Cu(2), and two equivalent Cu(1) atoms.
Na2MgNb2(CuS2)4 crystallizes in the monoclinic Pm space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a 3-coordinate geometry to one S(1) and two equivalent S(4) atoms. The Na(1)-S(1) bond length is 2.84 Å. Both Na(1)-S(4) bond lengths are 2.90 Å. In the second Na site, Na(2) is bonded in a distorted T-shaped geometry to one S(2) and two equivalent S(3) atoms. The Na(2)-S(2) bond length is 2.77 Å. Both Na(2)-S(3) bond lengths are 2.95 Å. Mg(1) is bonded in a 3-coordinate geometry to one Cu(3), one S(5), and two equivalent S(3) atoms. The Mg(1)-Cu(3) bond length is 2.74 Å. The Mg(1)-S(5) bond length is 2.46 Å. Both Mg(1)-S(3) bond lengths are 2.50 Å. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to one S(1), one S(6), and two equivalent S(3) atoms to form distorted NbS4 tetrahedra that share edges with two equivalent Cu(2)S4 tetrahedra. The Nb(1)-S(1) bond length is 2.28 Å. The Nb(1)-S(6) bond length is 2.39 Å. Both Nb(1)-S(3) bond lengths are 2.38 Å. In the second Nb site, Nb(2) is bonded in a distorted tetrahedral geometry to one S(2), one S(5), and two equivalent S(4) atoms. The Nb(2)-S(2) bond length is 2.33 Å. The Nb(2)-S(5) bond length is 2.42 Å. Both Nb(2)-S(4) bond lengths are 2.34 Å. There are three inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a 4-coordinate geometry to one S(3), one S(4), one S(5), and one S(6) atom. The Cu(1)-S(3) bond length is 2.42 Å. The Cu(1)-S(4) bond length is 2.41 Å. The Cu(1)-S(5) bond length is 2.39 Å. The Cu(1)-S(6) bond length is 2.32 Å. In the second Cu site, Cu(2) is bonded to one S(1), one S(6), and two equivalent S(3) atoms to form CuS4 tetrahedra that share edges with two equivalent Nb(1)S4 tetrahedra. The Cu(2)-S(1) bond length is 2.32 Å. The Cu(2)-S(6) bond length is 2.41 Å. Both Cu(2)-S(3) bond lengths are 2.38 Å. In the third Cu site, Cu(3) is bonded in a 5-coordinate geometry to one Mg(1), one S(2), one S(5), and two equivalent S(4) atoms. The Cu(3)-S(2) bond length is 2.24 Å. The Cu(3)-S(5) bond length is 2.54 Å. Both Cu(3)-S(4) bond lengths are 2.36 Å. There are six inequivalent S sites. In the first S site, S(1) is bonded in a distorted trigonal non-coplanar geometry to one Na(1), one Nb(1), and one Cu(2) atom. In the second S site, S(2) is bonded in a T-shaped geometry to one Na(2), one Nb(2), and one Cu(3) atom. In the third S site, S(3) is bonded in a distorted pentagonal planar geometry to one Na(2), one Mg(1), one Nb(1), one Cu(1), and one Cu(2) atom. In the fourth S site, S(4) is bonded in a 4-coordinate geometry to one Na(1), one Nb(2), one Cu(1), and one Cu(3) atom. In the fifth S site, S(5) is bonded in a distorted pentagonal planar geometry to one Mg(1), one Nb(2), one Cu(3), and two equivalent Cu(1) atoms. In the sixth S site, S(6) is bonded in a 4-coordinate geometry to one Nb(1), one Cu(2), and two equivalent Cu(1) atoms.