Na4Mg(WO4)2 crystallizes in the monoclinic Cm space group. There are three inequivalent Na sites. In the first Na site, Na(1) is bonded in a 6-coordinate geometry to one O(3), one O(6), two equivalent O(2), and two equivalent O(5) atoms. In the second Na site, Na(2) is bonded in a 5-coordinate geometry to one O(1), one O(2), one O(3), one O(4), and one O(6) atom. In the third Na site, Na(3) is bonded in a 6-coordinate geometry to one O(1), one O(4), two equivalent O(2), and two equivalent O(5) atoms. Mg(1) is bonded in a 4-coordinate geometry to one O(1), one O(3), and two equivalent O(5) atoms. There are two inequivalent W sites. In the first W site, W(1) is bonded in a distorted see-saw-like geometry to one O(1), one O(3), and two equivalent O(2) atoms. In the second W site, W(2) is bonded in an octahedral geometry to one O(4), one O(6), two equivalent O(2), and two equivalent O(5) atoms. There are six inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to one Na(3), two equivalent Na(2), one Mg(1), and one W(1) atom. In the second O site, O(2) is bonded in a 5-coordinate geometry to one Na(1), one Na(2), one Na(3), one W(1), and one W(2) atom. In the third O site, O(3) is bonded in a 5-coordinate geometry to one Na(1), two equivalent Na(2), one Mg(1), and one W(1) atom. In the fourth O site, O(4) is bonded to one Na(3), two equivalent Na(2), and one W(2) atom to form a mixture of corner and edge-sharing ONa3W tetrahedra. In the fifth O site, O(5) is bonded in a distorted rectangular see-saw-like geometry to one Na(1), one Na(3), one Mg(1), and one W(2) atom. In the sixth O site, O(6) is bonded to one Na(1), two equivalent Na(2), and one W(2) atom to form a mixture of corner and edge-sharing ONa3W tetrahedra.
Na4Mg(WO4)2 crystallizes in the monoclinic Cm space group. There are three inequivalent Na sites. In the first Na site, Na(1) is bonded in a 6-coordinate geometry to one O(3), one O(6), two equivalent O(2), and two equivalent O(5) atoms. The Na(1)-O(3) bond length is 2.44 Å. The Na(1)-O(6) bond length is 2.21 Å. Both Na(1)-O(2) bond lengths are 2.62 Å. Both Na(1)-O(5) bond lengths are 2.42 Å. In the second Na site, Na(2) is bonded in a 5-coordinate geometry to one O(1), one O(2), one O(3), one O(4), and one O(6) atom. The Na(2)-O(1) bond length is 2.49 Å. The Na(2)-O(2) bond length is 2.38 Å. The Na(2)-O(3) bond length is 2.48 Å. The Na(2)-O(4) bond length is 2.24 Å. The Na(2)-O(6) bond length is 2.25 Å. In the third Na site, Na(3) is bonded in a 6-coordinate geometry to one O(1), one O(4), two equivalent O(2), and two equivalent O(5) atoms. The Na(3)-O(1) bond length is 2.44 Å. The Na(3)-O(4) bond length is 2.21 Å. Both Na(3)-O(2) bond lengths are 2.62 Å. Both Na(3)-O(5) bond lengths are 2.41 Å. Mg(1) is bonded in a 4-coordinate geometry to one O(1), one O(3), and two equivalent O(5) atoms. The Mg(1)-O(1) bond length is 2.05 Å. The Mg(1)-O(3) bond length is 2.05 Å. Both Mg(1)-O(5) bond lengths are 2.02 Å. There are two inequivalent W sites. In the first W site, W(1) is bonded in a distorted see-saw-like geometry to one O(1), one O(3), and two equivalent O(2) atoms. The W(1)-O(1) bond length is 1.93 Å. The W(1)-O(3) bond length is 1.93 Å. Both W(1)-O(2) bond lengths are 1.91 Å. In the second W site, W(2) is bonded in an octahedral geometry to one O(4), one O(6), two equivalent O(2), and two equivalent O(5) atoms. The W(2)-O(4) bond length is 1.88 Å. The W(2)-O(6) bond length is 1.88 Å. Both W(2)-O(2) bond lengths are 2.30 Å. Both W(2)-O(5) bond lengths are 2.02 Å. There are six inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to one Na(3), two equivalent Na(2), one Mg(1), and one W(1) atom. In the second O site, O(2) is bonded in a 5-coordinate geometry to one Na(1), one Na(2), one Na(3), one W(1), and one W(2) atom. In the third O site, O(3) is bonded in a 5-coordinate geometry to one Na(1), two equivalent Na(2), one Mg(1), and one W(1) atom. In the fourth O site, O(4) is bonded to one Na(3), two equivalent Na(2), and one W(2) atom to form a mixture of corner and edge-sharing ONa3W tetrahedra. In the fifth O site, O(5) is bonded in a distorted rectangular see-saw-like geometry to one Na(1), one Na(3), one Mg(1), and one W(2) atom. In the sixth O site, O(6) is bonded to one Na(1), two equivalent Na(2), and one W(2) atom to form a mixture of corner and edge-sharing ONa3W tetrahedra.