Na2O crystallizes in the hexagonal P-62m space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded to one O(2) and four equivalent O(1) atoms to form distorted NaO5 square pyramids that share corners with ten equivalent Na(1)O5 square pyramids, corners with six equivalent Na(2)O4 tetrahedra, edges with six equivalent Na(1)O5 square pyramids, and edges with six equivalent Na(2)O4 tetrahedra. In the second Na site, Na(2) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form distorted NaO4 tetrahedra that share corners with six equivalent Na(1)O5 square pyramids, corners with ten equivalent Na(2)O4 tetrahedra, edges with six equivalent Na(1)O5 square pyramids, and edges with two equivalent Na(2)O4 tetrahedra. There are two inequivalent O sites. In the first O site, O(1) is bonded in a 9-coordinate geometry to three equivalent Na(2) and six equivalent Na(1) atoms. In the second O site, O(2) is bonded in a 9-coordinate geometry to three equivalent Na(1) and six equivalent Na(2) atoms.
Na2O crystallizes in the hexagonal P-62m space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded to one O(2) and four equivalent O(1) atoms to form distorted NaO5 square pyramids that share corners with ten equivalent Na(1)O5 square pyramids, corners with six equivalent Na(2)O4 tetrahedra, edges with six equivalent Na(1)O5 square pyramids, and edges with six equivalent Na(2)O4 tetrahedra. The Na(1)-O(2) bond length is 2.51 Å. All Na(1)-O(1) bond lengths are 2.55 Å. In the second Na site, Na(2) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form distorted NaO4 tetrahedra that share corners with six equivalent Na(1)O5 square pyramids, corners with ten equivalent Na(2)O4 tetrahedra, edges with six equivalent Na(1)O5 square pyramids, and edges with two equivalent Na(2)O4 tetrahedra. Both Na(2)-O(1) bond lengths are 2.28 Å. Both Na(2)-O(2) bond lengths are 2.38 Å. There are two inequivalent O sites. In the first O site, O(1) is bonded in a 9-coordinate geometry to three equivalent Na(2) and six equivalent Na(1) atoms. In the second O site, O(2) is bonded in a 9-coordinate geometry to three equivalent Na(1) and six equivalent Na(2) atoms.