Na4MgV2O6 crystallizes in the triclinic P1 space group. There are four inequivalent Na sites. In the first Na site, Na(1) is bonded in a 5-coordinate geometry to one O(1), one O(2), one O(4), one O(5), and one O(6) atom. In the second Na site, Na(2) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom. In the third Na site, Na(3) is bonded to one O(1), one O(3), one O(4), one O(5), and one O(6) atom to form distorted NaO5 trigonal bipyramids that share corners with four equivalent V(2)O5 trigonal bipyramids, edges with two equivalent Mg(1)O5 trigonal bipyramids, and edges with two equivalent V(1)O5 trigonal bipyramids. In the fourth Na site, Na(4) is bonded in a 4-coordinate geometry to one O(2), one O(3), one O(4), and one O(6) atom. Mg(1) is bonded to one O(1), one O(2), one O(3), one O(5), and one O(6) atom to form MgO5 trigonal bipyramids that share corners with four equivalent V(1)O5 trigonal bipyramids, edges with two equivalent Na(3)O5 trigonal bipyramids, and edges with two equivalent V(2)O5 trigonal bipyramids. There are two inequivalent V sites. In the first V site, V(1) is bonded to one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form VO5 trigonal bipyramids that share corners with four equivalent Mg(1)O5 trigonal bipyramids, edges with two equivalent Na(3)O5 trigonal bipyramids, and edges with two equivalent V(2)O5 trigonal bipyramids. In the second V site, V(2) is bonded to one O(1), one O(2), one O(3), one O(4), and one O(5) atom to form VO5 trigonal bipyramids that share corners with four equivalent Na(3)O5 trigonal bipyramids, edges with two equivalent Mg(1)O5 trigonal bipyramids, and edges with two equivalent V(1)O5 trigonal bipyramids. There are six inequivalent O sites. In the first O site, O(1) is bonded to one Na(1), one Na(2), one Na(3), one Mg(1), and one V(2) atom to form distorted ONa3MgV trigonal bipyramids that share corners with two equivalent O(2)Na3MgV2 octahedra, corners with two equivalent O(4)Na4V2 pentagonal pyramids, corners with four equivalent O(3)Na3MgV2 pentagonal pyramids,  an edgeedge with one O(2)Na3MgV2 octahedra, and  an edgeedge with one O(4)Na4V2 pentagonal pyramid. The corner-sharing octahedral tilt angles range from 41-76°. In the second O site, O(2) is bonded to one Na(1), one Na(2), one Na(4), one Mg(1), one V(1), and one V(2) atom to form distorted ONa3MgV2 octahedra that share  a cornercorner with one O(4)Na4V2 pentagonal pyramid, corners with two equivalent O(1)Na3MgV trigonal bipyramids,  an edgeedge with one O(3)Na3MgV2 pentagonal pyramid, edges with two equivalent O(4)Na4V2 pentagonal pyramids,  an edgeedge with one O(1)Na3MgV trigonal bipyramid, and  a faceface with one O(3)Na3MgV2 pentagonal pyramid. In the third O site, O(3) is bonded to one Na(2), one Na(3), one Na(4), one Mg(1), one V(1), and one V(2) atom to form distorted ONa3MgV2 pentagonal pyramids that share corners with three equivalent O(4)Na4V2 pentagonal pyramids, corners with four equivalent O(1)Na3MgV trigonal bipyramids,  an edgeedge with one O(2)Na3MgV2 octahedra,  an edgeedge with one O(4)Na4V2 pentagonal pyramid, and  a faceface with one O(2)Na3MgV2 octahedra. In the fourth O site, O(4) is bonded to one Na(1), one Na(2), one Na(3), one Na(4), one V(1), and one V(2) atom to form distorted ONa4V2 pentagonal pyramids that share  a cornercorner with one O(2)Na3MgV2 octahedra, corners with three equivalent O(3)Na3MgV2 pentagonal pyramids, corners with two equivalent O(1)Na3MgV trigonal bipyramids, edges with two equivalent O(2)Na3MgV2 octahedra,  an edgeedge with one O(3)Na3MgV2 pentagonal pyramid, and  an edgeedge with one O(1)Na3MgV trigonal bipyramid. The corner-sharing octahedral tilt angles are 47°. In the fifth O site, O(5) is bonded in a 6-coordinate geometry to one Na(1), one Na(2), one Na(3), one Mg(1), one V(1), and one V(2) atom. In the sixth O site, O(6) is bonded in a 6-coordinate geometry to one Na(1), one Na(2), one Na(3), one Na(4), one Mg(1), and one V(1) atom.
Na4MgV2O6 crystallizes in the triclinic P1 space group. There are four inequivalent Na sites. In the first Na site, Na(1) is bonded in a 5-coordinate geometry to one O(1), one O(2), one O(4), one O(5), and one O(6) atom. The Na(1)-O(1) bond length is 2.38 Å. The Na(1)-O(2) bond length is 2.64 Å. The Na(1)-O(4) bond length is 2.38 Å. The Na(1)-O(5) bond length is 2.60 Å. The Na(1)-O(6) bond length is 2.51 Å. In the second Na site, Na(2) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom. The Na(2)-O(1) bond length is 2.24 Å. The Na(2)-O(2) bond length is 2.56 Å. The Na(2)-O(3) bond length is 2.31 Å. The Na(2)-O(4) bond length is 2.41 Å. The Na(2)-O(5) bond length is 2.48 Å. The Na(2)-O(6) bond length is 2.59 Å. In the third Na site, Na(3) is bonded to one O(1), one O(3), one O(4), one O(5), and one O(6) atom to form distorted NaO5 trigonal bipyramids that share corners with four equivalent V(2)O5 trigonal bipyramids, edges with two equivalent Mg(1)O5 trigonal bipyramids, and edges with two equivalent V(1)O5 trigonal bipyramids. The Na(3)-O(1) bond length is 2.23 Å. The Na(3)-O(3) bond length is 2.35 Å. The Na(3)-O(4) bond length is 2.36 Å. The Na(3)-O(5) bond length is 2.38 Å. The Na(3)-O(6) bond length is 2.32 Å. In the fourth Na site, Na(4) is bonded in a 4-coordinate geometry to one O(2), one O(3), one O(4), and one O(6) atom. The Na(4)-O(2) bond length is 2.33 Å. The Na(4)-O(3) bond length is 2.48 Å. The Na(4)-O(4) bond length is 2.21 Å. The Na(4)-O(6) bond length is 2.36 Å. Mg(1) is bonded to one O(1), one O(2), one O(3), one O(5), and one O(6) atom to form MgO5 trigonal bipyramids that share corners with four equivalent V(1)O5 trigonal bipyramids, edges with two equivalent Na(3)O5 trigonal bipyramids, and edges with two equivalent V(2)O5 trigonal bipyramids. The Mg(1)-O(1) bond length is 2.09 Å. The Mg(1)-O(2) bond length is 2.10 Å. The Mg(1)-O(3) bond length is 2.20 Å. The Mg(1)-O(5) bond length is 2.13 Å. The Mg(1)-O(6) bond length is 2.07 Å. There are two inequivalent V sites. In the first V site, V(1) is bonded to one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form VO5 trigonal bipyramids that share corners with four equivalent Mg(1)O5 trigonal bipyramids, edges with two equivalent Na(3)O5 trigonal bipyramids, and edges with two equivalent V(2)O5 trigonal bipyramids. The V(1)-O(2) bond length is 1.98 Å. The V(1)-O(3) bond length is 2.17 Å. The V(1)-O(4) bond length is 2.15 Å. The V(1)-O(5) bond length is 1.98 Å. The V(1)-O(6) bond length is 1.96 Å. In the second V site, V(2) is bonded to one O(1), one O(2), one O(3), one O(4), and one O(5) atom to form VO5 trigonal bipyramids that share corners with four equivalent Na(3)O5 trigonal bipyramids, edges with two equivalent Mg(1)O5 trigonal bipyramids, and edges with two equivalent V(1)O5 trigonal bipyramids. The V(2)-O(1) bond length is 1.94 Å. The V(2)-O(2) bond length is 2.20 Å. The V(2)-O(3) bond length is 1.94 Å. The V(2)-O(4) bond length is 1.95 Å. The V(2)-O(5) bond length is 2.13 Å. There are six inequivalent O sites. In the first O site, O(1) is bonded to one Na(1), one Na(2), one Na(3), one Mg(1), and one V(2) atom to form distorted ONa3MgV trigonal bipyramids that share corners with two equivalent O(2)Na3MgV2 octahedra, corners with two equivalent O(4)Na4V2 pentagonal pyramids, corners with four equivalent O(3)Na3MgV2 pentagonal pyramids,  an edgeedge with one O(2)Na3MgV2 octahedra, and  an edgeedge with one O(4)Na4V2 pentagonal pyramid. The corner-sharing octahedral tilt angles range from 41-76°. In the second O site, O(2) is bonded to one Na(1), one Na(2), one Na(4), one Mg(1), one V(1), and one V(2) atom to form distorted ONa3MgV2 octahedra that share  a cornercorner with one O(4)Na4V2 pentagonal pyramid, corners with two equivalent O(1)Na3MgV trigonal bipyramids,  an edgeedge with one O(3)Na3MgV2 pentagonal pyramid, edges with two equivalent O(4)Na4V2 pentagonal pyramids,  an edgeedge with one O(1)Na3MgV trigonal bipyramid, and  a faceface with one O(3)Na3MgV2 pentagonal pyramid. In the third O site, O(3) is bonded to one Na(2), one Na(3), one Na(4), one Mg(1), one V(1), and one V(2) atom to form distorted ONa3MgV2 pentagonal pyramids that share corners with three equivalent O(4)Na4V2 pentagonal pyramids, corners with four equivalent O(1)Na3MgV trigonal bipyramids,  an edgeedge with one O(2)Na3MgV2 octahedra,  an edgeedge with one O(4)Na4V2 pentagonal pyramid, and  a faceface with one O(2)Na3MgV2 octahedra. In the fourth O site, O(4) is bonded to one Na(1), one Na(2), one Na(3), one Na(4), one V(1), and one V(2) atom to form distorted ONa4V2 pentagonal pyramids that share  a cornercorner with one O(2)Na3MgV2 octahedra, corners with three equivalent O(3)Na3MgV2 pentagonal pyramids, corners with two equivalent O(1)Na3MgV trigonal bipyramids, edges with two equivalent O(2)Na3MgV2 octahedra,  an edgeedge with one O(3)Na3MgV2 pentagonal pyramid, and  an edgeedge with one O(1)Na3MgV trigonal bipyramid. The corner-sharing octahedral tilt angles are 47°. In the fifth O site, O(5) is bonded in a 6-coordinate geometry to one Na(1), one Na(2), one Na(3), one Mg(1), one V(1), and one V(2) atom. In the sixth O site, O(6) is bonded in a 6-coordinate geometry to one Na(1), one Na(2), one Na(3), one Na(4), one Mg(1), and one V(1) atom.