Na6Mg(NiO3)2 crystallizes in the triclinic P-1 space group. There are three inequivalent Na sites. In the first Na site, Na(1) is bonded in a 4-coordinate geometry to two equivalent O(2) and two equivalent O(3) atoms. In the second Na site, Na(2) is bonded in a 4-coordinate geometry to one O(2), one O(3), and two equivalent O(1) atoms. In the third Na site, Na(3) is bonded in a 4-coordinate geometry to one O(1), one O(3), and two equivalent O(2) atoms. Mg(1) is bonded in a square co-planar geometry to two equivalent O(1) and two equivalent O(2) atoms. Ni(1) is bonded in a 4-coordinate geometry to one O(1), one O(2), and two equivalent O(3) atoms. There are three 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 Ni(1) atom. In the second O site, O(2) is bonded to one Na(2), two equivalent Na(1), two equivalent Na(3), one Mg(1), and one Ni(1) atom to form a mixture of distorted corner and edge-sharing ONa5MgNi pentagonal bipyramids. In the third O site, O(3) is bonded in a 6-coordinate geometry to one Na(2), one Na(3), two equivalent Na(1), and two equivalent Ni(1) atoms.
Na6Mg(NiO3)2 crystallizes in the triclinic P-1 space group. There are three inequivalent Na sites. In the first Na site, Na(1) is bonded in a 4-coordinate geometry to two equivalent O(2) and two equivalent O(3) atoms. There is one shorter (2.50 Å) and one longer (2.56 Å) Na(1)-O(2) bond length. There is one shorter (2.33 Å) and one longer (2.45 Å) Na(1)-O(3) bond length. In the second Na site, Na(2) is bonded in a 4-coordinate geometry to one O(2), one O(3), and two equivalent O(1) atoms. The Na(2)-O(2) bond length is 2.39 Å. The Na(2)-O(3) bond length is 2.23 Å. There is one shorter (2.19 Å) and one longer (2.43 Å) Na(2)-O(1) bond length. In the third Na site, Na(3) is bonded in a 4-coordinate geometry to one O(1), one O(3), and two equivalent O(2) atoms. The Na(3)-O(1) bond length is 2.30 Å. The Na(3)-O(3) bond length is 2.67 Å. There is one shorter (2.38 Å) and one longer (2.40 Å) Na(3)-O(2) bond length. Mg(1) is bonded in a square co-planar geometry to two equivalent O(1) and two equivalent O(2) atoms. Both Mg(1)-O(1) bond lengths are 1.97 Å. Both Mg(1)-O(2) bond lengths are 2.12 Å. Ni(1) is bonded in a 4-coordinate geometry to one O(1), one O(2), and two equivalent O(3) atoms. The Ni(1)-O(1) bond length is 1.96 Å. The Ni(1)-O(2) bond length is 2.06 Å. There is one shorter (1.97 Å) and one longer (2.03 Å) Ni(1)-O(3) bond length. There are three 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 Ni(1) atom. In the second O site, O(2) is bonded to one Na(2), two equivalent Na(1), two equivalent Na(3), one Mg(1), and one Ni(1) atom to form a mixture of distorted corner and edge-sharing ONa5MgNi pentagonal bipyramids. In the third O site, O(3) is bonded in a 6-coordinate geometry to one Na(2), one Na(3), two equivalent Na(1), and two equivalent Ni(1) atoms.