NaU3O8 crystallizes in the hexagonal P-62m space group. Na(1) is bonded in a 9-coordinate geometry to three equivalent O(1) and six equivalent O(2) atoms. U(1) is bonded to two equivalent O(1), two equivalent O(3), and three equivalent O(2) atoms to form a mixture of distorted corner and edge-sharing UO7 pentagonal bipyramids. There are three inequivalent O sites. In the first O site, O(1) is bonded in a T-shaped geometry to one Na(1) and two equivalent U(1) atoms. In the second O site, O(2) is bonded in a 5-coordinate geometry to two equivalent Na(1) and three equivalent U(1) atoms. In the third O site, O(3) is bonded in a trigonal planar geometry to three equivalent U(1) atoms.
NaU3O8 crystallizes in the hexagonal P-62m space group. Na(1) is bonded in a 9-coordinate geometry to three equivalent O(1) and six equivalent O(2) atoms. All Na(1)-O(1) bond lengths are 2.37 Å. All Na(1)-O(2) bond lengths are 2.67 Å. U(1) is bonded to two equivalent O(1), two equivalent O(3), and three equivalent O(2) atoms to form a mixture of distorted corner and edge-sharing UO7 pentagonal bipyramids. Both U(1)-O(1) bond lengths are 2.10 Å. Both U(1)-O(3) bond lengths are 2.21 Å. There are two shorter (2.18 Å) and one longer (2.76 Å) U(1)-O(2) bond length. There are three inequivalent O sites. In the first O site, O(1) is bonded in a T-shaped geometry to one Na(1) and two equivalent U(1) atoms. In the second O site, O(2) is bonded in a 5-coordinate geometry to two equivalent Na(1) and three equivalent U(1) atoms. In the third O site, O(3) is bonded in a trigonal planar geometry to three equivalent U(1) atoms.