Na5MgBiO5 crystallizes in the triclinic P1 space group. There are five inequivalent Na sites. In the first Na site, Na(1) is bonded in a distorted trigonal non-coplanar geometry to one O(1), one O(2), and one O(5) atom. In the second Na site, Na(2) is bonded in a 4-coordinate geometry to one O(2), one O(3), one O(4), and one O(5) atom. In the third Na site, Na(3) is bonded in a trigonal non-coplanar geometry to one O(1), one O(3), and one O(4) atom. In the fourth Na site, Na(4) is bonded to one O(1), one O(2), one O(3), and one O(5) atom to form distorted NaO4 trigonal pyramids that share  a cornercorner with one Mg(1)O4 tetrahedra and  an edgeedge with one Mg(1)O4 tetrahedra. In the fifth Na site, Na(5) is bonded in a distorted T-shaped geometry to one O(3), one O(4), and one O(5) atom. Mg(1) is bonded to one O(1), one O(2), one O(4), and one O(5) atom to form MgO4 tetrahedra that share  a cornercorner with one Na(4)O4 trigonal pyramid and  an edgeedge with one Na(4)O4 trigonal pyramid. Bi(1) is bonded in a 4-coordinate geometry to one O(1), one O(2), one O(3), and one O(5) atom. There are five inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to one Na(1), one Na(3), one Na(4), one Mg(1), and one Bi(1) atom. In the second O site, O(2) is bonded in a 5-coordinate geometry to one Na(1), one Na(2), one Na(4), one Mg(1), and one Bi(1) atom. In the third O site, O(3) is bonded in a trigonal bipyramidal geometry to one Na(2), one Na(3), one Na(4), one Na(5), and one Bi(1) atom. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Na(2), one Na(3), one Na(5), and one Mg(1) atom. In the fifth O site, O(5) is bonded in a 6-coordinate geometry to one Na(1), one Na(2), one Na(4), one Na(5), one Mg(1), and one Bi(1) atom.
Na5MgBiO5 crystallizes in the triclinic P1 space group. There are five inequivalent Na sites. In the first Na site, Na(1) is bonded in a distorted trigonal non-coplanar geometry to one O(1), one O(2), and one O(5) atom. The Na(1)-O(1) bond length is 2.52 Å. The Na(1)-O(2) bond length is 2.31 Å. The Na(1)-O(5) bond length is 2.35 Å. In the second Na site, Na(2) is bonded in a 4-coordinate geometry to one O(2), one O(3), one O(4), and one O(5) atom. The Na(2)-O(2) bond length is 2.78 Å. The Na(2)-O(3) bond length is 2.34 Å. The Na(2)-O(4) bond length is 2.32 Å. The Na(2)-O(5) bond length is 2.41 Å. In the third Na site, Na(3) is bonded in a trigonal non-coplanar geometry to one O(1), one O(3), and one O(4) atom. The Na(3)-O(1) bond length is 2.30 Å. The Na(3)-O(3) bond length is 2.25 Å. The Na(3)-O(4) bond length is 2.30 Å. In the fourth Na site, Na(4) is bonded to one O(1), one O(2), one O(3), and one O(5) atom to form distorted NaO4 trigonal pyramids that share  a cornercorner with one Mg(1)O4 tetrahedra and  an edgeedge with one Mg(1)O4 tetrahedra. The Na(4)-O(1) bond length is 2.36 Å. The Na(4)-O(2) bond length is 2.52 Å. The Na(4)-O(3) bond length is 2.32 Å. The Na(4)-O(5) bond length is 2.36 Å. In the fifth Na site, Na(5) is bonded in a distorted T-shaped geometry to one O(3), one O(4), and one O(5) atom. The Na(5)-O(3) bond length is 2.36 Å. The Na(5)-O(4) bond length is 2.32 Å. The Na(5)-O(5) bond length is 2.42 Å. Mg(1) is bonded to one O(1), one O(2), one O(4), and one O(5) atom to form MgO4 tetrahedra that share  a cornercorner with one Na(4)O4 trigonal pyramid and  an edgeedge with one Na(4)O4 trigonal pyramid. The Mg(1)-O(1) bond length is 2.02 Å. The Mg(1)-O(2) bond length is 2.04 Å. The Mg(1)-O(4) bond length is 1.97 Å. The Mg(1)-O(5) bond length is 2.05 Å. Bi(1) is bonded in a 4-coordinate geometry to one O(1), one O(2), one O(3), and one O(5) atom. The Bi(1)-O(1) bond length is 2.32 Å. The Bi(1)-O(2) bond length is 2.19 Å. The Bi(1)-O(3) bond length is 2.17 Å. The Bi(1)-O(5) bond length is 2.48 Å. There are five inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to one Na(1), one Na(3), one Na(4), one Mg(1), and one Bi(1) atom. In the second O site, O(2) is bonded in a 5-coordinate geometry to one Na(1), one Na(2), one Na(4), one Mg(1), and one Bi(1) atom. In the third O site, O(3) is bonded in a trigonal bipyramidal geometry to one Na(2), one Na(3), one Na(4), one Na(5), and one Bi(1) atom. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Na(2), one Na(3), one Na(5), and one Mg(1) atom. In the fifth O site, O(5) is bonded in a 6-coordinate geometry to one Na(1), one Na(2), one Na(4), one Na(5), one Mg(1), and one Bi(1) atom.