Na2MgV2Cd2O8 crystallizes in the monoclinic C2/m space group. Na(1) is bonded in a 2-coordinate geometry to one O(2) and one O(3) atom. Mg(1) is bonded in a distorted linear geometry to two equivalent O(3) atoms. V(1) is bonded to one O(2), one O(3), and two equivalent O(1) atoms to form VO4 tetrahedra that share corners with three equivalent Cd(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 33-48°. There are two inequivalent Cd sites. In the first Cd site, Cd(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form CdO6 octahedra that share corners with six equivalent V(1)O4 tetrahedra. In the second Cd site, Cd(2) is bonded in a 4-coordinate geometry to four equivalent O(1) atoms. There are three inequivalent O sites. In the first O site, O(1) is bonded in a 1-coordinate geometry to one V(1), one Cd(1), and one Cd(2) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Na(1), one V(1), and one Cd(1) atom. In the third O site, O(3) is bonded in a T-shaped geometry to one Na(1), one Mg(1), and one V(1) atom.
Na2MgV2Cd2O8 crystallizes in the monoclinic C2/m space group. Na(1) is bonded in a 2-coordinate geometry to one O(2) and one O(3) atom. The Na(1)-O(2) bond length is 2.30 Å. The Na(1)-O(3) bond length is 2.51 Å. Mg(1) is bonded in a distorted linear geometry to two equivalent O(3) atoms. Both Mg(1)-O(3) bond lengths are 1.96 Å. V(1) is bonded to one O(2), one O(3), and two equivalent O(1) atoms to form VO4 tetrahedra that share corners with three equivalent Cd(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 33-48°. The V(1)-O(2) bond length is 1.72 Å. The V(1)-O(3) bond length is 1.78 Å. Both V(1)-O(1) bond lengths are 1.76 Å. There are two inequivalent Cd sites. In the first Cd site, Cd(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form CdO6 octahedra that share corners with six equivalent V(1)O4 tetrahedra. Both Cd(1)-O(2) bond lengths are 2.27 Å. All Cd(1)-O(1) bond lengths are 2.38 Å. In the second Cd site, Cd(2) is bonded in a 4-coordinate geometry to four equivalent O(1) atoms. All Cd(2)-O(1) bond lengths are 2.81 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded in a 1-coordinate geometry to one V(1), one Cd(1), and one Cd(2) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Na(1), one V(1), and one Cd(1) atom. In the third O site, O(3) is bonded in a T-shaped geometry to one Na(1), one Mg(1), and one V(1) atom.