Na17Al5O16 crystallizes in the monoclinic Cm space group. There are nine inequivalent Na sites. In the first Na site, Na(1) is bonded in a distorted see-saw-like geometry to one O(7), one O(8), and two equivalent O(2) atoms. In the second Na site, Na(2) is bonded in a 4-coordinate geometry to one O(3), one O(4), one O(5), and one O(9) atom. In the third Na site, Na(3) is bonded in a 5-coordinate geometry to one O(3), one O(5), one O(7), one O(8), and one O(9) atom. In the fourth Na site, Na(4) is bonded in a 5-coordinate geometry to one O(1), one O(4), one O(5), one O(6), and one O(9) atom. In the fifth Na site, Na(5) is bonded in a 3-coordinate geometry to one O(2), one O(3), one O(7), and one O(8) atom. In the sixth Na site, Na(6) is bonded in a 5-coordinate geometry to one O(3), one O(5), one O(7), one O(8), and one O(9) atom. In the seventh Na site, Na(7) is bonded in a 5-coordinate geometry to one O(1), one O(4), one O(5), one O(6), and one O(9) atom. In the eighth Na site, Na(8) is bonded in a 4-coordinate geometry to one O(7), one O(8), and two equivalent O(2) atoms. In the ninth Na site, Na(9) is bonded in a 4-coordinate geometry to one O(1), one O(6), and two equivalent O(4) atoms. There are three inequivalent Al sites. In the first Al site, Al(1) is bonded to one O(2), one O(3), one O(7), and one O(8) atom to form corner-sharing AlO4 tetrahedra. In the second Al site, Al(2) is bonded to one O(3), one O(4), one O(5), and one O(9) atom to form corner-sharing AlO4 tetrahedra. In the third Al site, Al(3) is bonded to one O(1), one O(6), and two equivalent O(4) atoms to form corner-sharing AlO4 tetrahedra. There are nine inequivalent O sites. In the first O site, O(1) is bonded in a 6-coordinate geometry to one Na(9), two equivalent Na(4), two equivalent Na(7), and one Al(3) atom. In the second O site, O(2) is bonded in a 6-coordinate geometry to one Na(5), two equivalent Na(1), two equivalent Na(8), and one Al(1) atom. In the third O site, O(3) is bonded in a 6-coordinate geometry to one Na(2), one Na(3), one Na(5), one Na(6), one Al(1), and one Al(2) atom. In the fourth O site, O(4) is bonded to one Na(2), one Na(4), one Na(7), one Na(9), one Al(2), and one Al(3) atom to form distorted edge-sharing ONa4Al2 octahedra. In the fifth O site, O(5) is bonded in a 6-coordinate geometry to one Na(2), one Na(3), one Na(4), one Na(6), one Na(7), and one Al(2) atom. In the sixth O site, O(6) is bonded in a 6-coordinate geometry to one Na(9), two equivalent Na(4), two equivalent Na(7), and one Al(3) atom. In the seventh O site, O(7) is bonded in a 6-coordinate geometry to one Na(1), one Na(3), one Na(5), one Na(6), one Na(8), and one Al(1) atom. In the eighth O site, O(8) is bonded in a 6-coordinate geometry to one Na(1), one Na(3), one Na(5), one Na(6), one Na(8), and one Al(1) atom. In the ninth O site, O(9) is bonded in a 6-coordinate geometry to one Na(2), one Na(3), one Na(4), one Na(6), one Na(7), and one Al(2) atom.
Na17Al5O16 crystallizes in the monoclinic Cm space group. There are nine inequivalent Na sites. In the first Na site, Na(1) is bonded in a distorted see-saw-like geometry to one O(7), one O(8), and two equivalent O(2) atoms. The Na(1)-O(7) bond length is 2.47 Å. The Na(1)-O(8) bond length is 2.28 Å. There is one shorter (2.37 Å) and one longer (2.56 Å) Na(1)-O(2) bond length. In the second Na site, Na(2) is bonded in a 4-coordinate geometry to one O(3), one O(4), one O(5), and one O(9) atom. The Na(2)-O(3) bond length is 2.32 Å. The Na(2)-O(4) bond length is 2.63 Å. The Na(2)-O(5) bond length is 2.41 Å. The Na(2)-O(9) bond length is 2.43 Å. In the third Na site, Na(3) is bonded in a 5-coordinate geometry to one O(3), one O(5), one O(7), one O(8), and one O(9) atom. The Na(3)-O(3) bond length is 2.42 Å. The Na(3)-O(5) bond length is 2.28 Å. The Na(3)-O(7) bond length is 2.64 Å. The Na(3)-O(8) bond length is 2.26 Å. The Na(3)-O(9) bond length is 2.52 Å. In the fourth Na site, Na(4) is bonded in a 5-coordinate geometry to one O(1), one O(4), one O(5), one O(6), and one O(9) atom. The Na(4)-O(1) bond length is 2.59 Å. The Na(4)-O(4) bond length is 2.39 Å. The Na(4)-O(5) bond length is 2.64 Å. The Na(4)-O(6) bond length is 2.26 Å. The Na(4)-O(9) bond length is 2.25 Å. In the fifth Na site, Na(5) is bonded in a 3-coordinate geometry to one O(2), one O(3), one O(7), and one O(8) atom. The Na(5)-O(2) bond length is 2.24 Å. The Na(5)-O(3) bond length is 2.87 Å. The Na(5)-O(7) bond length is 2.44 Å. The Na(5)-O(8) bond length is 2.36 Å. In the sixth Na site, Na(6) is bonded in a 5-coordinate geometry to one O(3), one O(5), one O(7), one O(8), and one O(9) atom. The Na(6)-O(3) bond length is 2.42 Å. The Na(6)-O(5) bond length is 2.47 Å. The Na(6)-O(7) bond length is 2.29 Å. The Na(6)-O(8) bond length is 2.73 Å. The Na(6)-O(9) bond length is 2.26 Å. In the seventh Na site, Na(7) is bonded in a 5-coordinate geometry to one O(1), one O(4), one O(5), one O(6), and one O(9) atom. The Na(7)-O(1) bond length is 2.26 Å. The Na(7)-O(4) bond length is 2.39 Å. The Na(7)-O(5) bond length is 2.26 Å. The Na(7)-O(6) bond length is 2.57 Å. The Na(7)-O(9) bond length is 2.66 Å. In the eighth Na site, Na(8) is bonded in a 4-coordinate geometry to one O(7), one O(8), and two equivalent O(2) atoms. The Na(8)-O(7) bond length is 2.22 Å. The Na(8)-O(8) bond length is 2.39 Å. There is one shorter (2.21 Å) and one longer (2.33 Å) Na(8)-O(2) bond length. In the ninth Na site, Na(9) is bonded in a 4-coordinate geometry to one O(1), one O(6), and two equivalent O(4) atoms. The Na(9)-O(1) bond length is 2.44 Å. The Na(9)-O(6) bond length is 2.44 Å. Both Na(9)-O(4) bond lengths are 2.45 Å. There are three inequivalent Al sites. In the first Al site, Al(1) is bonded to one O(2), one O(3), one O(7), and one O(8) atom to form corner-sharing AlO4 tetrahedra. The Al(1)-O(2) bond length is 1.76 Å. The Al(1)-O(3) bond length is 1.80 Å. The Al(1)-O(7) bond length is 1.76 Å. The Al(1)-O(8) bond length is 1.76 Å. In the second Al site, Al(2) is bonded to one O(3), one O(4), one O(5), and one O(9) atom to form corner-sharing AlO4 tetrahedra. The Al(2)-O(3) bond length is 1.77 Å. The Al(2)-O(4) bond length is 1.78 Å. The Al(2)-O(5) bond length is 1.75 Å. The Al(2)-O(9) bond length is 1.74 Å. In the third Al site, Al(3) is bonded to one O(1), one O(6), and two equivalent O(4) atoms to form corner-sharing AlO4 tetrahedra. The Al(3)-O(1) bond length is 1.74 Å. The Al(3)-O(6) bond length is 1.74 Å. Both Al(3)-O(4) bond lengths are 1.77 Å. There are nine inequivalent O sites. In the first O site, O(1) is bonded in a 6-coordinate geometry to one Na(9), two equivalent Na(4), two equivalent Na(7), and one Al(3) atom. In the second O site, O(2) is bonded in a 6-coordinate geometry to one Na(5), two equivalent Na(1), two equivalent Na(8), and one Al(1) atom. In the third O site, O(3) is bonded in a 6-coordinate geometry to one Na(2), one Na(3), one Na(5), one Na(6), one Al(1), and one Al(2) atom. In the fourth O site, O(4) is bonded to one Na(2), one Na(4), one Na(7), one Na(9), one Al(2), and one Al(3) atom to form distorted edge-sharing ONa4Al2 octahedra. In the fifth O site, O(5) is bonded in a 6-coordinate geometry to one Na(2), one Na(3), one Na(4), one Na(6), one Na(7), and one Al(2) atom. In the sixth O site, O(6) is bonded in a 6-coordinate geometry to one Na(9), two equivalent Na(4), two equivalent Na(7), and one Al(3) atom. In the seventh O site, O(7) is bonded in a 6-coordinate geometry to one Na(1), one Na(3), one Na(5), one Na(6), one Na(8), and one Al(1) atom. In the eighth O site, O(8) is bonded in a 6-coordinate geometry to one Na(1), one Na(3), one Na(5), one Na(6), one Na(8), and one Al(1) atom. In the ninth O site, O(9) is bonded in a 6-coordinate geometry to one Na(2), one Na(3), one Na(4), one Na(6), one Na(7), and one Al(2) atom.