Na6O crystallizes in the orthorhombic Cmm2 space group. There are eight inequivalent Na sites. In the first Na site, Na(1) is bonded in a single-bond geometry to two equivalent Na(5) and one O(1) atom. In the second Na site, Na(2) is bonded in a single-bond geometry to one Na(4), one Na(7), and one O(1) atom. In the third Na site, Na(3) is bonded in a bent 150 degrees geometry to two equivalent Na(4) and two equivalent O(1) atoms. In the fourth Na site, Na(4) is bonded in a 8-coordinate geometry to two equivalent Na(2), two equivalent Na(3), two equivalent Na(5), and two equivalent Na(6) atoms. In the fifth Na site, Na(5) is bonded in a 8-coordinate geometry to two equivalent Na(1), two equivalent Na(4), two equivalent Na(5), and two equivalent Na(6) atoms. In the sixth Na site, Na(6) is bonded in a single-bond geometry to one Na(4), one Na(5), one Na(7), and one O(2) atom. In the seventh Na site, Na(7) is bonded in a 8-coordinate geometry to four equivalent Na(2) and four equivalent Na(6) atoms. In the eighth Na site, Na(8) is bonded in a single-bond geometry to one O(2) atom. There are two inequivalent O sites. In the first O site, O(1) is bonded to one Na(1), two equivalent Na(2), and two equivalent Na(3) atoms to form distorted corner-sharing ONa5 square pyramids. In the second O site, O(2) is bonded in a distorted trigonal bipyramidal geometry to one Na(8) and four equivalent Na(6) atoms.
Na6O crystallizes in the orthorhombic Cmm2 space group. There are eight inequivalent Na sites. In the first Na site, Na(1) is bonded in a single-bond geometry to two equivalent Na(5) and one O(1) atom. Both Na(1)-Na(5) bond lengths are 3.76 Å. The Na(1)-O(1) bond length is 2.19 Å. In the second Na site, Na(2) is bonded in a single-bond geometry to one Na(4), one Na(7), and one O(1) atom. The Na(2)-Na(4) bond length is 3.64 Å. The Na(2)-Na(7) bond length is 3.67 Å. The Na(2)-O(1) bond length is 2.26 Å. In the third Na site, Na(3) is bonded in a bent 150 degrees geometry to two equivalent Na(4) and two equivalent O(1) atoms. Both Na(3)-Na(4) bond lengths are 3.78 Å. Both Na(3)-O(1) bond lengths are 2.26 Å. In the fourth Na site, Na(4) is bonded in a 8-coordinate geometry to two equivalent Na(2), two equivalent Na(3), two equivalent Na(5), and two equivalent Na(6) atoms. Both Na(4)-Na(5) bond lengths are 3.58 Å. Both Na(4)-Na(6) bond lengths are 3.69 Å. In the fifth Na site, Na(5) is bonded in a 8-coordinate geometry to two equivalent Na(1), two equivalent Na(4), two equivalent Na(5), and two equivalent Na(6) atoms. Both Na(5)-Na(5) bond lengths are 3.32 Å. Both Na(5)-Na(6) bond lengths are 3.45 Å. In the sixth Na site, Na(6) is bonded in a single-bond geometry to one Na(4), one Na(5), one Na(7), and one O(2) atom. The Na(6)-Na(7) bond length is 3.71 Å. The Na(6)-O(2) bond length is 2.24 Å. In the seventh Na site, Na(7) is bonded in a 8-coordinate geometry to four equivalent Na(2) and four equivalent Na(6) atoms. In the eighth Na site, Na(8) is bonded in a single-bond geometry to one O(2) atom. The Na(8)-O(2) bond length is 2.19 Å. There are two inequivalent O sites. In the first O site, O(1) is bonded to one Na(1), two equivalent Na(2), and two equivalent Na(3) atoms to form distorted corner-sharing ONa5 square pyramids. In the second O site, O(2) is bonded in a distorted trigonal bipyramidal geometry to one Na(8) and four equivalent Na(6) atoms.