Na3OsO5 crystallizes in the trigonal P3_121 space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a 6-coordinate geometry to one O(2), two equivalent O(3), and three equivalent O(1) atoms. In the second Na site, Na(2) is bonded in a 6-coordinate geometry to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms. Os(1) is bonded in a trigonal bipyramidal geometry to one O(2), two equivalent O(1), and two equivalent O(3) atoms. There are three inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to one Na(2), three equivalent Na(1), and one Os(1) atom. In the second O site, O(2) is bonded in a 5-coordinate geometry to two equivalent Na(1), two equivalent Na(2), and one Os(1) atom. In the third O site, O(3) is bonded in a distorted see-saw-like geometry to one Na(2), two equivalent Na(1), and one Os(1) atom.
Na3OsO5 crystallizes in the trigonal P3_121 space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a 6-coordinate geometry to one O(2), two equivalent O(3), and three equivalent O(1) atoms. The Na(1)-O(2) bond length is 2.40 Å. There is one shorter (2.29 Å) and one longer (2.35 Å) Na(1)-O(3) bond length. There are a spread of Na(1)-O(1) bond distances ranging from 2.42-2.71 Å. In the second Na site, Na(2) is bonded in a 6-coordinate geometry to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms. Both Na(2)-O(1) bond lengths are 2.29 Å. Both Na(2)-O(2) bond lengths are 2.71 Å. Both Na(2)-O(3) bond lengths are 2.28 Å. Os(1) is bonded in a trigonal bipyramidal geometry to one O(2), two equivalent O(1), and two equivalent O(3) atoms. The Os(1)-O(2) bond length is 1.77 Å. Both Os(1)-O(1) bond lengths are 1.87 Å. Both Os(1)-O(3) bond lengths are 1.83 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to one Na(2), three equivalent Na(1), and one Os(1) atom. In the second O site, O(2) is bonded in a 5-coordinate geometry to two equivalent Na(1), two equivalent Na(2), and one Os(1) atom. In the third O site, O(3) is bonded in a distorted see-saw-like geometry to one Na(2), two equivalent Na(1), and one Os(1) atom.