Na5MgReO6 crystallizes in the monoclinic Cm space group. There are three inequivalent Na sites. In the first Na site, Na(1) is bonded to one O(1), one O(4), two equivalent O(2), and two equivalent O(3) atoms to form distorted NaO6 octahedra that share corners with two equivalent Re(1)O6 octahedra, edges with two equivalent Re(1)O6 octahedra, and edges with three equivalent Na(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 5-15°. In the second Na site, Na(2) is bonded in a 4-coordinate geometry to one O(1), one O(2), and two equivalent O(3) atoms. In the third Na site, Na(3) is bonded in a 5-coordinate geometry to one O(4), two equivalent O(2), and two equivalent O(3) atoms. Mg(1) is bonded in a rectangular see-saw-like geometry to one O(1), one O(4), and two equivalent O(2) atoms. Re(1) is bonded to one O(1), one O(4), two equivalent O(2), and two equivalent O(3) atoms to form ReO6 octahedra that share corners with four equivalent Na(1)O6 octahedra and edges with four equivalent Na(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 5-15°. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 6-coordinate geometry to two equivalent Na(1), two equivalent Na(2), one Mg(1), and one Re(1) atom. In the second O site, O(2) is bonded in a 6-coordinate geometry to one Na(2), one Na(3), two equivalent Na(1), one Mg(1), and one Re(1) atom. In the third O site, O(3) is bonded in a 6-coordinate geometry to one Na(3), two equivalent Na(1), two equivalent Na(2), and one Re(1) atom. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to one Na(3), two equivalent Na(1), one Mg(1), and one Re(1) atom.
Na5MgReO6 crystallizes in the monoclinic Cm space group. There are three inequivalent Na sites. In the first Na site, Na(1) is bonded to one O(1), one O(4), two equivalent O(2), and two equivalent O(3) atoms to form distorted NaO6 octahedra that share corners with two equivalent Re(1)O6 octahedra, edges with two equivalent Re(1)O6 octahedra, and edges with three equivalent Na(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 5-15°. The Na(1)-O(1) bond length is 2.43 Å. The Na(1)-O(4) bond length is 2.46 Å. There is one shorter (2.52 Å) and one longer (2.79 Å) Na(1)-O(2) bond length. There is one shorter (2.51 Å) and one longer (2.84 Å) Na(1)-O(3) bond length. In the second Na site, Na(2) is bonded in a 4-coordinate geometry to one O(1), one O(2), and two equivalent O(3) atoms. The Na(2)-O(1) bond length is 2.51 Å. The Na(2)-O(2) bond length is 2.23 Å. There is one shorter (2.26 Å) and one longer (2.28 Å) Na(2)-O(3) bond length. In the third Na site, Na(3) is bonded in a 5-coordinate geometry to one O(4), two equivalent O(2), and two equivalent O(3) atoms. The Na(3)-O(4) bond length is 2.22 Å. Both Na(3)-O(2) bond lengths are 2.42 Å. Both Na(3)-O(3) bond lengths are 2.43 Å. Mg(1) is bonded in a rectangular see-saw-like geometry to one O(1), one O(4), and two equivalent O(2) atoms. The Mg(1)-O(1) bond length is 1.91 Å. The Mg(1)-O(4) bond length is 1.99 Å. Both Mg(1)-O(2) bond lengths are 2.02 Å. Re(1) is bonded to one O(1), one O(4), two equivalent O(2), and two equivalent O(3) atoms to form ReO6 octahedra that share corners with four equivalent Na(1)O6 octahedra and edges with four equivalent Na(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 5-15°. The Re(1)-O(1) bond length is 2.09 Å. The Re(1)-O(4) bond length is 2.07 Å. Both Re(1)-O(2) bond lengths are 2.12 Å. Both Re(1)-O(3) bond lengths are 1.92 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 6-coordinate geometry to two equivalent Na(1), two equivalent Na(2), one Mg(1), and one Re(1) atom. In the second O site, O(2) is bonded in a 6-coordinate geometry to one Na(2), one Na(3), two equivalent Na(1), one Mg(1), and one Re(1) atom. In the third O site, O(3) is bonded in a 6-coordinate geometry to one Na(3), two equivalent Na(1), two equivalent Na(2), and one Re(1) atom. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to one Na(3), two equivalent Na(1), one Mg(1), and one Re(1) atom.