Na2Ta2O5 crystallizes in the orthorhombic Ima2 space group. Na(1) is bonded in a 8-coordinate geometry to one O(3), three equivalent O(2), and four equivalent O(1) atoms. There are two inequivalent Ta sites. In the first Ta site, Ta(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form corner-sharing TaO6 octahedra. The corner-sharing octahedral tilt angles are 5°. In the second Ta site, Ta(2) is bonded in a rectangular see-saw-like geometry to two equivalent O(2) and two equivalent O(3) atoms. There are three inequivalent O sites. In the first O site, O(1) is bonded to four equivalent Na(1) and two equivalent Ta(1) atoms to form a mixture of distorted edge, face, and corner-sharing ONa4Ta2 octahedra. The corner-sharing octahedra are not tilted. In the second O site, O(2) is bonded in a 5-coordinate geometry to three equivalent Na(1), one Ta(1), and one Ta(2) atom. In the third O site, O(3) is bonded in a distorted linear geometry to two equivalent Na(1) and two equivalent Ta(2) atoms.
Na2Ta2O5 crystallizes in the orthorhombic Ima2 space group. Na(1) is bonded in a 8-coordinate geometry to one O(3), three equivalent O(2), and four equivalent O(1) atoms. The Na(1)-O(3) bond length is 2.81 Å. There are a spread of Na(1)-O(2) bond distances ranging from 2.59-2.86 Å. There are a spread of Na(1)-O(1) bond distances ranging from 2.72-2.77 Å. There are two inequivalent Ta sites. In the first Ta site, Ta(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form corner-sharing TaO6 octahedra. The corner-sharing octahedral tilt angles are 5°. Both Ta(1)-O(2) bond lengths are 2.02 Å. There are two shorter (1.99 Å) and two longer (2.00 Å) Ta(1)-O(1) bond lengths. In the second Ta site, Ta(2) is bonded in a rectangular see-saw-like geometry to two equivalent O(2) and two equivalent O(3) atoms. Both Ta(2)-O(2) bond lengths are 1.95 Å. There is one shorter (1.95 Å) and one longer (1.96 Å) Ta(2)-O(3) bond length. There are three inequivalent O sites. In the first O site, O(1) is bonded to four equivalent Na(1) and two equivalent Ta(1) atoms to form a mixture of distorted edge, face, and corner-sharing ONa4Ta2 octahedra. The corner-sharing octahedra are not tilted. In the second O site, O(2) is bonded in a 5-coordinate geometry to three equivalent Na(1), one Ta(1), and one Ta(2) atom. In the third O site, O(3) is bonded in a distorted linear geometry to two equivalent Na(1) and two equivalent Ta(2) atoms.