Na4MgO3 crystallizes in the monoclinic Cc space group. There are four inequivalent Na sites. In the first Na site, Na(1) is bonded in a 4-coordinate geometry to one O(2), one O(3), and two equivalent O(1) atoms. In the second Na site, Na(2) is bonded to one O(1), one O(2), and two equivalent O(3) atoms to form a mixture of distorted corner and edge-sharing NaO4 trigonal pyramids. In the third Na site, Na(3) is bonded in a trigonal planar geometry to one O(1), one O(2), and one O(3) atom. In the fourth Na site, Na(4) is bonded to one O(1), one O(3), and two equivalent O(2) atoms to form a mixture of distorted corner and edge-sharing NaO4 trigonal pyramids. Mg(1) is bonded in a trigonal planar geometry to one O(1), one O(2), and one O(3) atom. There are three inequivalent O sites. In the first O site, O(1) is bonded to one Na(2), one Na(3), one Na(4), two equivalent Na(1), and one Mg(1) atom to form corner-sharing ONa5Mg octahedra. The corner-sharing octahedral tilt angles are 66°. In the second O site, O(2) is bonded in a 6-coordinate geometry to one Na(1), one Na(2), one Na(3), two equivalent Na(4), and one Mg(1) atom. In the third O site, O(3) is bonded in a 6-coordinate geometry to one Na(1), one Na(3), one Na(4), two equivalent Na(2), and one Mg(1) atom.
Na4MgO3 crystallizes in the monoclinic Cc space group. There are four inequivalent Na sites. In the first Na site, Na(1) is bonded in a 4-coordinate geometry to one O(2), one O(3), and two equivalent O(1) atoms. The Na(1)-O(2) bond length is 2.36 Å. The Na(1)-O(3) bond length is 2.65 Å. There is one shorter (2.39 Å) and one longer (2.44 Å) Na(1)-O(1) bond length. In the second Na site, Na(2) is bonded to one O(1), one O(2), and two equivalent O(3) atoms to form a mixture of distorted corner and edge-sharing NaO4 trigonal pyramids. The Na(2)-O(1) bond length is 2.31 Å. The Na(2)-O(2) bond length is 2.63 Å. There is one shorter (2.31 Å) and one longer (2.33 Å) Na(2)-O(3) bond length. In the third Na site, Na(3) is bonded in a trigonal planar geometry to one O(1), one O(2), and one O(3) atom. The Na(3)-O(1) bond length is 2.30 Å. The Na(3)-O(2) bond length is 2.29 Å. The Na(3)-O(3) bond length is 2.22 Å. In the fourth Na site, Na(4) is bonded to one O(1), one O(3), and two equivalent O(2) atoms to form a mixture of distorted corner and edge-sharing NaO4 trigonal pyramids. The Na(4)-O(1) bond length is 2.39 Å. The Na(4)-O(3) bond length is 2.44 Å. There is one shorter (2.34 Å) and one longer (2.37 Å) Na(4)-O(2) bond length. Mg(1) is bonded in a trigonal planar geometry to one O(1), one O(2), and one O(3) atom. The Mg(1)-O(1) bond length is 1.94 Å. The Mg(1)-O(2) bond length is 1.93 Å. The Mg(1)-O(3) bond length is 1.94 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded to one Na(2), one Na(3), one Na(4), two equivalent Na(1), and one Mg(1) atom to form corner-sharing ONa5Mg octahedra. The corner-sharing octahedral tilt angles are 66°. In the second O site, O(2) is bonded in a 6-coordinate geometry to one Na(1), one Na(2), one Na(3), two equivalent Na(4), and one Mg(1) atom. In the third O site, O(3) is bonded in a 6-coordinate geometry to one Na(1), one Na(3), one Na(4), two equivalent Na(2), and one Mg(1) atom.