Na6Mg(SbO4)2 crystallizes in the triclinic P1 space group. There are six inequivalent Na sites. In the first Na site, Na(1) is bonded in a 5-coordinate geometry to one O(1), one O(3), one O(4), one O(6), and one O(7) atom. In the second Na site, Na(2) is bonded in a see-saw-like geometry to one O(1), one O(2), one O(3), and one O(7) atom. In the third Na site, Na(3) is bonded in a 3-coordinate geometry to one O(5), one O(6), and one O(8) atom. In the fourth Na site, Na(4) is bonded in a 4-coordinate geometry to one O(1), one O(2), one O(5), and one O(8) atom. In the fifth Na site, Na(5) is bonded to one O(1), one O(2), one O(3), and one O(6) atom to form distorted NaO4 trigonal pyramids that share corners with three equivalent Na(6)O4 tetrahedra,  a cornercorner with one Mg(1)O5 trigonal bipyramid,  a cornercorner with one Sb(1)O5 trigonal bipyramid, and  an edgeedge with one Sb(1)O5 trigonal bipyramid. In the sixth Na site, Na(6) is bonded to one O(1), one O(2), one O(4), and one O(6) atom to form NaO4 tetrahedra that share  a cornercorner with one Mg(1)O5 trigonal bipyramid,  a cornercorner with one Sb(1)O5 trigonal bipyramid, corners with three equivalent Na(5)O4 trigonal pyramids, and  an edgeedge with one Sb(1)O5 trigonal bipyramid. Mg(1) is bonded to one O(3), one O(4), one O(5), one O(7), and one O(8) atom to form distorted MgO5 trigonal bipyramids that share  a cornercorner with one Na(6)O4 tetrahedra,  a cornercorner with one Na(5)O4 trigonal pyramid, and  an edgeedge with one Sb(1)O5 trigonal bipyramid. There are two inequivalent Sb sites. In the first Sb site, Sb(1) is bonded to one O(1), one O(2), one O(5), one O(6), and one O(8) atom to form SbO5 trigonal bipyramids that share  a cornercorner with one Na(6)O4 tetrahedra,  a cornercorner with one Na(5)O4 trigonal pyramid,  an edgeedge with one Na(6)O4 tetrahedra,  an edgeedge with one Mg(1)O5 trigonal bipyramid, and  an edgeedge with one Na(5)O4 trigonal pyramid. In the second Sb site, Sb(2) is bonded in a distorted trigonal non-coplanar geometry to one O(3), one O(4), and one O(7) atom. There are eight inequivalent O sites. In the first O site, O(1) is bonded to one Na(1), one Na(2), one Na(4), one Na(5), one Na(6), and one Sb(1) atom to form distorted ONa5Sb octahedra that share  a cornercorner with one O(3)Na3MgSb trigonal bipyramid,  a cornercorner with one O(2)Na4Sb trigonal bipyramid,  a cornercorner with one O(6)Na4Sb trigonal bipyramid, corners with two equivalent O(8)Na2MgSb trigonal pyramids,  an edgeedge with one O(5)Na2MgSb tetrahedra,  an edgeedge with one O(7)Na2MgSb tetrahedra,  an edgeedge with one O(3)Na3MgSb trigonal bipyramid, edges with two equivalent O(2)Na4Sb trigonal bipyramids, and  a faceface with one O(6)Na4Sb trigonal bipyramid. In the second O site, O(2) is bonded to one Na(2), one Na(4), one Na(5), one Na(6), and one Sb(1) atom to form distorted ONa4Sb trigonal bipyramids that share  a cornercorner with one O(1)Na5Sb octahedra,  a cornercorner with one O(7)Na2MgSb tetrahedra, corners with two equivalent O(5)Na2MgSb tetrahedra, corners with three equivalent O(6)Na4Sb trigonal bipyramids, edges with two equivalent O(1)Na5Sb octahedra,  an edgeedge with one O(3)Na3MgSb trigonal bipyramid, and  an edgeedge with one O(8)Na2MgSb trigonal pyramid. The corner-sharing octahedral tilt angles are 32°. In the third O site, O(3) is bonded to one Na(1), one Na(2), one Na(5), one Mg(1), and one Sb(2) atom to form distorted ONa3MgSb trigonal bipyramids that share  a cornercorner with one O(1)Na5Sb octahedra,  a cornercorner with one O(5)Na2MgSb tetrahedra,  a cornercorner with one O(8)Na2MgSb trigonal pyramid,  an edgeedge with one O(1)Na5Sb octahedra, edges with two equivalent O(7)Na2MgSb tetrahedra,  an edgeedge with one O(2)Na4Sb trigonal bipyramid, and  an edgeedge with one O(6)Na4Sb trigonal bipyramid. The corner-sharing octahedral tilt angles are 57°. In the fourth O site, O(4) is bonded in a distorted rectangular see-saw-like geometry to one Na(1), one Na(6), one Mg(1), and one Sb(2) atom. In the fifth O site, O(5) is bonded to one Na(3), one Na(4), one Mg(1), and one Sb(1) atom to form distorted ONa2MgSb tetrahedra that share  a cornercorner with one O(7)Na2MgSb tetrahedra,  a cornercorner with one O(3)Na3MgSb trigonal bipyramid, corners with two equivalent O(2)Na4Sb trigonal bipyramids, corners with two equivalent O(6)Na4Sb trigonal bipyramids, corners with two equivalent O(8)Na2MgSb trigonal pyramids,  an edgeedge with one O(1)Na5Sb octahedra, and  an edgeedge with one O(8)Na2MgSb trigonal pyramid. In the sixth O site, O(6) is bonded to one Na(1), one Na(3), one Na(5), one Na(6), and one Sb(1) atom to form distorted ONa4Sb trigonal bipyramids that share  a cornercorner with one O(1)Na5Sb octahedra,  a cornercorner with one O(7)Na2MgSb tetrahedra, corners with two equivalent O(5)Na2MgSb tetrahedra, corners with three equivalent O(2)Na4Sb trigonal bipyramids,  an edgeedge with one O(3)Na3MgSb trigonal bipyramid,  an edgeedge with one O(8)Na2MgSb trigonal pyramid, and  a faceface with one O(1)Na5Sb octahedra. The corner-sharing octahedral tilt angles are 76°. In the seventh O site, O(7) is bonded to one Na(1), one Na(2), one Mg(1), and one Sb(2) atom to form ONa2MgSb tetrahedra that share  a cornercorner with one O(5)Na2MgSb tetrahedra,  a cornercorner with one O(2)Na4Sb trigonal bipyramid,  a cornercorner with one O(6)Na4Sb trigonal bipyramid,  a cornercorner with one O(8)Na2MgSb trigonal pyramid,  an edgeedge with one O(1)Na5Sb octahedra, and edges with two equivalent O(3)Na3MgSb trigonal bipyramids. In the eighth O site, O(8) is bonded to one Na(3), one Na(4), one Mg(1), and one Sb(1) atom to form ONa2MgSb trigonal pyramids that share corners with two equivalent O(1)Na5Sb octahedra,  a cornercorner with one O(7)Na2MgSb tetrahedra, corners with two equivalent O(5)Na2MgSb tetrahedra,  a cornercorner with one O(3)Na3MgSb trigonal bipyramid,  an edgeedge with one O(5)Na2MgSb tetrahedra,  an edgeedge with one O(2)Na4Sb trigonal bipyramid, and  an edgeedge with one O(6)Na4Sb trigonal bipyramid. The corner-sharing octahedral tilt angles range from 15-51°.
Na6Mg(SbO4)2 crystallizes in the triclinic P1 space group. There are six inequivalent Na sites. In the first Na site, Na(1) is bonded in a 5-coordinate geometry to one O(1), one O(3), one O(4), one O(6), and one O(7) atom. The Na(1)-O(1) bond length is 2.77 Å. The Na(1)-O(3) bond length is 2.34 Å. The Na(1)-O(4) bond length is 2.42 Å. The Na(1)-O(6) bond length is 2.68 Å. The Na(1)-O(7) bond length is 2.39 Å. In the second Na site, Na(2) is bonded in a see-saw-like geometry to one O(1), one O(2), one O(3), and one O(7) atom. The Na(2)-O(1) bond length is 2.40 Å. The Na(2)-O(2) bond length is 2.41 Å. The Na(2)-O(3) bond length is 2.36 Å. The Na(2)-O(7) bond length is 2.26 Å. In the third Na site, Na(3) is bonded in a 3-coordinate geometry to one O(5), one O(6), and one O(8) atom. The Na(3)-O(5) bond length is 2.25 Å. The Na(3)-O(6) bond length is 2.40 Å. The Na(3)-O(8) bond length is 2.22 Å. In the fourth Na site, Na(4) is bonded in a 4-coordinate geometry to one O(1), one O(2), one O(5), and one O(8) atom. The Na(4)-O(1) bond length is 2.33 Å. The Na(4)-O(2) bond length is 2.42 Å. The Na(4)-O(5) bond length is 2.24 Å. The Na(4)-O(8) bond length is 2.33 Å. In the fifth Na site, Na(5) is bonded to one O(1), one O(2), one O(3), and one O(6) atom to form distorted NaO4 trigonal pyramids that share corners with three equivalent Na(6)O4 tetrahedra,  a cornercorner with one Mg(1)O5 trigonal bipyramid,  a cornercorner with one Sb(1)O5 trigonal bipyramid, and  an edgeedge with one Sb(1)O5 trigonal bipyramid. The Na(5)-O(1) bond length is 2.28 Å. The Na(5)-O(2) bond length is 2.24 Å. The Na(5)-O(3) bond length is 2.41 Å. The Na(5)-O(6) bond length is 2.39 Å. In the sixth Na site, Na(6) is bonded to one O(1), one O(2), one O(4), and one O(6) atom to form NaO4 tetrahedra that share  a cornercorner with one Mg(1)O5 trigonal bipyramid,  a cornercorner with one Sb(1)O5 trigonal bipyramid, corners with three equivalent Na(5)O4 trigonal pyramids, and  an edgeedge with one Sb(1)O5 trigonal bipyramid. The Na(6)-O(1) bond length is 2.36 Å. The Na(6)-O(2) bond length is 2.38 Å. The Na(6)-O(4) bond length is 2.31 Å. The Na(6)-O(6) bond length is 2.25 Å. Mg(1) is bonded to one O(3), one O(4), one O(5), one O(7), and one O(8) atom to form distorted MgO5 trigonal bipyramids that share  a cornercorner with one Na(6)O4 tetrahedra,  a cornercorner with one Na(5)O4 trigonal pyramid, and  an edgeedge with one Sb(1)O5 trigonal bipyramid. The Mg(1)-O(3) bond length is 2.50 Å. The Mg(1)-O(4) bond length is 2.12 Å. The Mg(1)-O(5) bond length is 2.00 Å. The Mg(1)-O(7) bond length is 2.03 Å. The Mg(1)-O(8) bond length is 2.13 Å. There are two inequivalent Sb sites. In the first Sb site, Sb(1) is bonded to one O(1), one O(2), one O(5), one O(6), and one O(8) atom to form SbO5 trigonal bipyramids that share  a cornercorner with one Na(6)O4 tetrahedra,  a cornercorner with one Na(5)O4 trigonal pyramid,  an edgeedge with one Na(6)O4 tetrahedra,  an edgeedge with one Mg(1)O5 trigonal bipyramid, and  an edgeedge with one Na(5)O4 trigonal pyramid. The Sb(1)-O(1) bond length is 2.00 Å. The Sb(1)-O(2) bond length is 1.96 Å. The Sb(1)-O(5) bond length is 1.99 Å. The Sb(1)-O(6) bond length is 1.97 Å. The Sb(1)-O(8) bond length is 2.01 Å. In the second Sb site, Sb(2) is bonded in a distorted trigonal non-coplanar geometry to one O(3), one O(4), and one O(7) atom. The Sb(2)-O(3) bond length is 1.98 Å. The Sb(2)-O(4) bond length is 2.01 Å. The Sb(2)-O(7) bond length is 2.00 Å. There are eight inequivalent O sites. In the first O site, O(1) is bonded to one Na(1), one Na(2), one Na(4), one Na(5), one Na(6), and one Sb(1) atom to form distorted ONa5Sb octahedra that share  a cornercorner with one O(3)Na3MgSb trigonal bipyramid,  a cornercorner with one O(2)Na4Sb trigonal bipyramid,  a cornercorner with one O(6)Na4Sb trigonal bipyramid, corners with two equivalent O(8)Na2MgSb trigonal pyramids,  an edgeedge with one O(5)Na2MgSb tetrahedra,  an edgeedge with one O(7)Na2MgSb tetrahedra,  an edgeedge with one O(3)Na3MgSb trigonal bipyramid, edges with two equivalent O(2)Na4Sb trigonal bipyramids, and  a faceface with one O(6)Na4Sb trigonal bipyramid. In the second O site, O(2) is bonded to one Na(2), one Na(4), one Na(5), one Na(6), and one Sb(1) atom to form distorted ONa4Sb trigonal bipyramids that share  a cornercorner with one O(1)Na5Sb octahedra,  a cornercorner with one O(7)Na2MgSb tetrahedra, corners with two equivalent O(5)Na2MgSb tetrahedra, corners with three equivalent O(6)Na4Sb trigonal bipyramids, edges with two equivalent O(1)Na5Sb octahedra,  an edgeedge with one O(3)Na3MgSb trigonal bipyramid, and  an edgeedge with one O(8)Na2MgSb trigonal pyramid. The corner-sharing octahedral tilt angles are 32°. In the third O site, O(3) is bonded to one Na(1), one Na(2), one Na(5), one Mg(1), and one Sb(2) atom to form distorted ONa3MgSb trigonal bipyramids that share  a cornercorner with one O(1)Na5Sb octahedra,  a cornercorner with one O(5)Na2MgSb tetrahedra,  a cornercorner with one O(8)Na2MgSb trigonal pyramid,  an edgeedge with one O(1)Na5Sb octahedra, edges with two equivalent O(7)Na2MgSb tetrahedra,  an edgeedge with one O(2)Na4Sb trigonal bipyramid, and  an edgeedge with one O(6)Na4Sb trigonal bipyramid. The corner-sharing octahedral tilt angles are 57°. In the fourth O site, O(4) is bonded in a distorted rectangular see-saw-like geometry to one Na(1), one Na(6), one Mg(1), and one Sb(2) atom. In the fifth O site, O(5) is bonded to one Na(3), one Na(4), one Mg(1), and one Sb(1) atom to form distorted ONa2MgSb tetrahedra that share  a cornercorner with one O(7)Na2MgSb tetrahedra,  a cornercorner with one O(3)Na3MgSb trigonal bipyramid, corners with two equivalent O(2)Na4Sb trigonal bipyramids, corners with two equivalent O(6)Na4Sb trigonal bipyramids, corners with two equivalent O(8)Na2MgSb trigonal pyramids,  an edgeedge with one O(1)Na5Sb octahedra, and  an edgeedge with one O(8)Na2MgSb trigonal pyramid. In the sixth O site, O(6) is bonded to one Na(1), one Na(3), one Na(5), one Na(6), and one Sb(1) atom to form distorted ONa4Sb trigonal bipyramids that share  a cornercorner with one O(1)Na5Sb octahedra,  a cornercorner with one O(7)Na2MgSb tetrahedra, corners with two equivalent O(5)Na2MgSb tetrahedra, corners with three equivalent O(2)Na4Sb trigonal bipyramids,  an edgeedge with one O(3)Na3MgSb trigonal bipyramid,  an edgeedge with one O(8)Na2MgSb trigonal pyramid, and  a faceface with one O(1)Na5Sb octahedra. The corner-sharing octahedral tilt angles are 76°. In the seventh O site, O(7) is bonded to one Na(1), one Na(2), one Mg(1), and one Sb(2) atom to form ONa2MgSb tetrahedra that share  a cornercorner with one O(5)Na2MgSb tetrahedra,  a cornercorner with one O(2)Na4Sb trigonal bipyramid,  a cornercorner with one O(6)Na4Sb trigonal bipyramid,  a cornercorner with one O(8)Na2MgSb trigonal pyramid,  an edgeedge with one O(1)Na5Sb octahedra, and edges with two equivalent O(3)Na3MgSb trigonal bipyramids. In the eighth O site, O(8) is bonded to one Na(3), one Na(4), one Mg(1), and one Sb(1) atom to form ONa2MgSb trigonal pyramids that share corners with two equivalent O(1)Na5Sb octahedra,  a cornercorner with one O(7)Na2MgSb tetrahedra, corners with two equivalent O(5)Na2MgSb tetrahedra,  a cornercorner with one O(3)Na3MgSb trigonal bipyramid,  an edgeedge with one O(5)Na2MgSb tetrahedra,  an edgeedge with one O(2)Na4Sb trigonal bipyramid, and  an edgeedge with one O(6)Na4Sb trigonal bipyramid. The corner-sharing octahedral tilt angles range from 15-51°.