Na5MgSbO5 crystallizes in the monoclinic C2/m space group. There are three inequivalent Na sites. In the first Na site, Na(1) is bonded in a 5-coordinate geometry to one Mg(1), one O(2), one O(3), and three equivalent O(1) atoms. In the second Na site, Na(2) is bonded in a 5-coordinate geometry to one Mg(1), one O(1), one O(3), and three equivalent O(2) atoms. In the third Na site, Na(3) is bonded to two equivalent Mg(1), two equivalent O(1), and two equivalent O(2) atoms to form distorted NaMg2O4 octahedra that share corners with two equivalent Na(3)Mg2O4 octahedra and edges with two equivalent Sb(1)O6 octahedra. The corner-sharing octahedra are not tilted. Mg(1) is bonded to two equivalent Na(1), two equivalent Na(2), and two equivalent Na(3) atoms to form MgNa6 octahedra that share corners with two equivalent Mg(1)Na6 octahedra, corners with four equivalent O(1)Na5Sb octahedra, edges with two equivalent O(3)Na4Sb2 octahedra, and edges with four equivalent O(1)Na5Sb octahedra. The corner-sharing octahedral tilt angles range from 0-13°. Sb(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form SbO6 octahedra that share corners with two equivalent Sb(1)O6 octahedra and edges with two equivalent Na(3)Mg2O4 octahedra. The corner-sharing octahedra are not tilted. There are three inequivalent O sites. In the first O site, O(1) is bonded to one Na(2), one Na(3), three equivalent Na(1), and one Sb(1) atom to form distorted ONa5Sb octahedra that share corners with two equivalent Mg(1)Na6 octahedra, corners with four equivalent O(1)Na5Sb octahedra, edges with two equivalent Mg(1)Na6 octahedra, edges with two equivalent O(1)Na5Sb octahedra, and edges with three equivalent O(3)Na4Sb2 octahedra. The corner-sharing octahedral tilt angles range from 0-28°. In the second O site, O(2) is bonded in a 6-coordinate geometry to one Na(1), one Na(3), three equivalent Na(2), and one Sb(1) atom. In the third O site, O(3) is bonded to two equivalent Na(1), two equivalent Na(2), and two equivalent Sb(1) atoms to form ONa4Sb2 octahedra that share corners with two equivalent O(3)Na4Sb2 octahedra, edges with two equivalent Mg(1)Na6 octahedra, and edges with six equivalent O(1)Na5Sb octahedra. The corner-sharing octahedra are not tilted.
Na5MgSbO5 crystallizes in the monoclinic C2/m space group. There are three inequivalent Na sites. In the first Na site, Na(1) is bonded in a 5-coordinate geometry to one Mg(1), one O(2), one O(3), and three equivalent O(1) atoms. The Na(1)-Mg(1) bond length is 2.81 Å. The Na(1)-O(2) bond length is 2.45 Å. The Na(1)-O(3) bond length is 2.39 Å. There is one shorter (2.32 Å) and two longer (2.49 Å) Na(1)-O(1) bond lengths. In the second Na site, Na(2) is bonded in a 5-coordinate geometry to one Mg(1), one O(1), one O(3), and three equivalent O(2) atoms. The Na(2)-Mg(1) bond length is 2.89 Å. The Na(2)-O(1) bond length is 2.33 Å. The Na(2)-O(3) bond length is 2.59 Å. There are two shorter (2.51 Å) and one longer (2.85 Å) Na(2)-O(2) bond length. In the third Na site, Na(3) is bonded to two equivalent Mg(1), two equivalent O(1), and two equivalent O(2) atoms to form distorted NaMg2O4 octahedra that share corners with two equivalent Na(3)Mg2O4 octahedra and edges with two equivalent Sb(1)O6 octahedra. The corner-sharing octahedra are not tilted. Both Na(3)-Mg(1) bond lengths are 2.41 Å. Both Na(3)-O(1) bond lengths are 2.33 Å. Both Na(3)-O(2) bond lengths are 2.45 Å. Mg(1) is bonded to two equivalent Na(1), two equivalent Na(2), and two equivalent Na(3) atoms to form MgNa6 octahedra that share corners with two equivalent Mg(1)Na6 octahedra, corners with four equivalent O(1)Na5Sb octahedra, edges with two equivalent O(3)Na4Sb2 octahedra, and edges with four equivalent O(1)Na5Sb octahedra. The corner-sharing octahedral tilt angles range from 0-13°. Sb(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form SbO6 octahedra that share corners with two equivalent Sb(1)O6 octahedra and edges with two equivalent Na(3)Mg2O4 octahedra. The corner-sharing octahedra are not tilted. Both Sb(1)-O(1) bond lengths are 2.02 Å. Both Sb(1)-O(2) bond lengths are 2.02 Å. Both Sb(1)-O(3) bond lengths are 2.41 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded to one Na(2), one Na(3), three equivalent Na(1), and one Sb(1) atom to form distorted ONa5Sb octahedra that share corners with two equivalent Mg(1)Na6 octahedra, corners with four equivalent O(1)Na5Sb octahedra, edges with two equivalent Mg(1)Na6 octahedra, edges with two equivalent O(1)Na5Sb octahedra, and edges with three equivalent O(3)Na4Sb2 octahedra. The corner-sharing octahedral tilt angles range from 0-28°. In the second O site, O(2) is bonded in a 6-coordinate geometry to one Na(1), one Na(3), three equivalent Na(2), and one Sb(1) atom. In the third O site, O(3) is bonded to two equivalent Na(1), two equivalent Na(2), and two equivalent Sb(1) atoms to form ONa4Sb2 octahedra that share corners with two equivalent O(3)Na4Sb2 octahedra, edges with two equivalent Mg(1)Na6 octahedra, and edges with six equivalent O(1)Na5Sb octahedra. The corner-sharing octahedra are not tilted.