Na2O crystallizes in the trigonal P321 space group. There are three 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 Na(1,1)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 Na(1,1)O5 square pyramids; corners with ten equivalent Na(2)O4 tetrahedra; edges with six Na(1,1)O5 square pyramids; and edges with two equivalent Na(2)O4 tetrahedra. In the third 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 Na(1,1)O5 square pyramids; corners with six equivalent Na(2)O4 tetrahedra; edges with six Na(1,1)O5 square pyramids; and edges with six 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 Na(1,1) atoms. In the second O site, O(2) is bonded in a 9-coordinate geometry to three Na(1,1) and six equivalent Na(2) atoms.
Na2O crystallizes in the trigonal P321 space group. There are three 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 Na(1,1)O5 square pyramids; and edges with six equivalent Na(2)O4 tetrahedra. The Na(1)-O(2) bond length is 2.52 Å. There are two shorter (2.51 Å) and two longer (2.59 Å) Na(1)-O(1) bond lengths. 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 Na(1,1)O5 square pyramids; corners with ten equivalent Na(2)O4 tetrahedra; edges with six Na(1,1)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 2.37 Å. In the third 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 Na(1,1)O5 square pyramids; corners with six equivalent Na(2)O4 tetrahedra; edges with six Na(1,1)O5 square pyramids; and edges with six equivalent Na(2)O4 tetrahedra. The Na(1)-O(2) bond length is 2.52 Å. There are two shorter (2.51 Å) and two longer (2.59 Å) Na(1)-O(1) bond lengths. 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 Na(1,1) atoms. In the second O site, O(2) is bonded in a 9-coordinate geometry to three Na(1,1) and six equivalent Na(2) atoms.