Na4Mg(CuO2)4 crystallizes in the triclinic P-1 space group. There are three inequivalent Na sites. In the first Na site, Na(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms to form edge-sharing NaO6 octahedra. In the second Na site, Na(2) is bonded in a 5-coordinate geometry to one O(4), two equivalent O(1), and two equivalent O(3) atoms. In the third Na site, Na(3) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms to form distorted edge-sharing NaO6 octahedra. Mg(1) is bonded in a 4-coordinate geometry to two equivalent O(2) and two equivalent O(3) atoms. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a distorted rectangular see-saw-like geometry to one O(1), one O(2), one O(3), and one O(4) atom. In the second Cu site, Cu(2) is bonded in a square co-planar geometry to one O(1), one O(2), one O(3), and one O(4) atom. There are four inequivalent O sites. In the first O site, O(1) is bonded to one Na(1), two equivalent Na(2), one Cu(1), and one Cu(2) atom to form a mixture of distorted corner and edge-sharing ONa3Cu2 trigonal bipyramids. In the second O site, O(2) is bonded in a distorted pentagonal planar geometry to one Na(1), one Na(3), one Mg(1), one Cu(1), and one Cu(2) atom. In the third O site, O(3) is bonded in a 6-coordinate geometry to one Na(3), two equivalent Na(2), one Mg(1), one Cu(1), and one Cu(2) atom. In the fourth O site, O(4) is bonded to one Na(1), one Na(2), one Na(3), one Cu(1), and one Cu(2) atom to form a mixture of distorted corner and edge-sharing ONa3Cu2 trigonal bipyramids.
Na4Mg(CuO2)4 crystallizes in the triclinic P-1 space group. There are three inequivalent Na sites. In the first Na site, Na(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms to form edge-sharing NaO6 octahedra. Both Na(1)-O(1) bond lengths are 2.38 Å. Both Na(1)-O(2) bond lengths are 2.56 Å. Both Na(1)-O(4) bond lengths are 2.34 Å. In the second Na site, Na(2) is bonded in a 5-coordinate geometry to one O(4), two equivalent O(1), and two equivalent O(3) atoms. The Na(2)-O(4) bond length is 2.43 Å. There is one shorter (2.35 Å) and one longer (2.48 Å) Na(2)-O(1) bond length. There is one shorter (2.27 Å) and one longer (2.66 Å) Na(2)-O(3) bond length. In the third Na site, Na(3) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms to form distorted edge-sharing NaO6 octahedra. Both Na(3)-O(2) bond lengths are 2.47 Å. Both Na(3)-O(3) bond lengths are 2.74 Å. Both Na(3)-O(4) bond lengths are 2.37 Å. Mg(1) is bonded in a 4-coordinate geometry to two equivalent O(2) and two equivalent O(3) atoms. Both Mg(1)-O(2) bond lengths are 2.10 Å. Both Mg(1)-O(3) bond lengths are 2.05 Å. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a distorted rectangular see-saw-like geometry to one O(1), one O(2), one O(3), and one O(4) atom. The Cu(1)-O(1) bond length is 1.87 Å. The Cu(1)-O(2) bond length is 1.94 Å. The Cu(1)-O(3) bond length is 1.97 Å. The Cu(1)-O(4) bond length is 1.88 Å. In the second Cu site, Cu(2) is bonded in a square co-planar geometry to one O(1), one O(2), one O(3), and one O(4) atom. The Cu(2)-O(1) bond length is 1.92 Å. The Cu(2)-O(2) bond length is 1.97 Å. The Cu(2)-O(3) bond length is 1.94 Å. The Cu(2)-O(4) bond length is 1.90 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded to one Na(1), two equivalent Na(2), one Cu(1), and one Cu(2) atom to form a mixture of distorted corner and edge-sharing ONa3Cu2 trigonal bipyramids. In the second O site, O(2) is bonded in a distorted pentagonal planar geometry to one Na(1), one Na(3), one Mg(1), one Cu(1), and one Cu(2) atom. In the third O site, O(3) is bonded in a 6-coordinate geometry to one Na(3), two equivalent Na(2), one Mg(1), one Cu(1), and one Cu(2) atom. In the fourth O site, O(4) is bonded to one Na(1), one Na(2), one Na(3), one Cu(1), and one Cu(2) atom to form a mixture of distorted corner and edge-sharing ONa3Cu2 trigonal bipyramids.