Na3NbOF6 crystallizes in the orthorhombic P2_12_12_1 space group. There are three inequivalent Na sites. In the first Na site, Na(1) is bonded to one O(1), one F(1), one F(2), one F(3), one F(4), one F(5), and one F(6) atom to form distorted NaOF6 pentagonal bipyramids that share corners with five equivalent Nb(1)OF6 pentagonal bipyramids and  an edgeedge with one Nb(1)OF6 pentagonal bipyramid. In the second Na site, Na(2) is bonded in a 7-coordinate geometry to one O(1), one F(1), one F(4), two equivalent F(2), and two equivalent F(3) atoms. In the third Na site, Na(3) is bonded in a 7-coordinate geometry to one O(1), one F(1), one F(4), two equivalent F(5), and two equivalent F(6) atoms. Nb(1) is bonded to one O(1), one F(1), one F(2), one F(3), one F(4), one F(5), and one F(6) atom to form NbOF6 pentagonal bipyramids that share corners with five equivalent Na(1)OF6 pentagonal bipyramids and  an edgeedge with one Na(1)OF6 pentagonal bipyramid. O(1) is bonded in a 4-coordinate geometry to one Na(1), one Na(2), one Na(3), and one Nb(1) atom. There are six inequivalent F sites. In the first F site, F(1) is bonded to one Na(1), one Na(2), one Na(3), and one Nb(1) atom to form a mixture of corner and edge-sharing FNa3Nb tetrahedra. In the second F site, F(2) is bonded to one Na(1), two equivalent Na(2), and one Nb(1) atom to form distorted corner-sharing FNa3Nb tetrahedra. In the third F site, F(3) is bonded in a 4-coordinate geometry to one Na(1), two equivalent Na(2), and one Nb(1) atom. In the fourth F site, F(4) is bonded in a distorted see-saw-like geometry to one Na(1), one Na(2), one Na(3), and one Nb(1) atom. In the fifth F site, F(5) is bonded to one Na(1), two equivalent Na(3), and one Nb(1) atom to form a mixture of distorted corner and edge-sharing FNa3Nb tetrahedra. In the sixth F site, F(6) is bonded to one Na(1), two equivalent Na(3), and one Nb(1) atom to form a mixture of distorted corner and edge-sharing FNa3Nb tetrahedra.
Na3NbOF6 crystallizes in the orthorhombic P2_12_12_1 space group. There are three inequivalent Na sites. In the first Na site, Na(1) is bonded to one O(1), one F(1), one F(2), one F(3), one F(4), one F(5), and one F(6) atom to form distorted NaOF6 pentagonal bipyramids that share corners with five equivalent Nb(1)OF6 pentagonal bipyramids and  an edgeedge with one Nb(1)OF6 pentagonal bipyramid. The Na(1)-O(1) bond length is 2.39 Å. The Na(1)-F(1) bond length is 2.26 Å. The Na(1)-F(2) bond length is 2.46 Å. The Na(1)-F(3) bond length is 2.69 Å. The Na(1)-F(4) bond length is 2.51 Å. The Na(1)-F(5) bond length is 2.44 Å. The Na(1)-F(6) bond length is 2.45 Å. In the second Na site, Na(2) is bonded in a 7-coordinate geometry to one O(1), one F(1), one F(4), two equivalent F(2), and two equivalent F(3) atoms. The Na(2)-O(1) bond length is 2.70 Å. The Na(2)-F(1) bond length is 2.43 Å. The Na(2)-F(4) bond length is 2.54 Å. There is one shorter (2.34 Å) and one longer (2.35 Å) Na(2)-F(2) bond length. There is one shorter (2.29 Å) and one longer (2.41 Å) Na(2)-F(3) bond length. In the third Na site, Na(3) is bonded in a 7-coordinate geometry to one O(1), one F(1), one F(4), two equivalent F(5), and two equivalent F(6) atoms. The Na(3)-O(1) bond length is 2.60 Å. The Na(3)-F(1) bond length is 2.53 Å. The Na(3)-F(4) bond length is 2.47 Å. There is one shorter (2.31 Å) and one longer (2.63 Å) Na(3)-F(5) bond length. There is one shorter (2.31 Å) and one longer (2.36 Å) Na(3)-F(6) bond length. Nb(1) is bonded to one O(1), one F(1), one F(2), one F(3), one F(4), one F(5), and one F(6) atom to form NbOF6 pentagonal bipyramids that share corners with five equivalent Na(1)OF6 pentagonal bipyramids and  an edgeedge with one Na(1)OF6 pentagonal bipyramid. The Nb(1)-O(1) bond length is 1.78 Å. The Nb(1)-F(1) bond length is 2.14 Å. The Nb(1)-F(2) bond length is 2.09 Å. The Nb(1)-F(3) bond length is 2.06 Å. The Nb(1)-F(4) bond length is 2.06 Å. The Nb(1)-F(5) bond length is 2.07 Å. The Nb(1)-F(6) bond length is 2.09 Å. O(1) is bonded in a 4-coordinate geometry to one Na(1), one Na(2), one Na(3), and one Nb(1) atom. There are six inequivalent F sites. In the first F site, F(1) is bonded to one Na(1), one Na(2), one Na(3), and one Nb(1) atom to form a mixture of corner and edge-sharing FNa3Nb tetrahedra. In the second F site, F(2) is bonded to one Na(1), two equivalent Na(2), and one Nb(1) atom to form distorted corner-sharing FNa3Nb tetrahedra. In the third F site, F(3) is bonded in a 4-coordinate geometry to one Na(1), two equivalent Na(2), and one Nb(1) atom. In the fourth F site, F(4) is bonded in a distorted see-saw-like geometry to one Na(1), one Na(2), one Na(3), and one Nb(1) atom. In the fifth F site, F(5) is bonded to one Na(1), two equivalent Na(3), and one Nb(1) atom to form a mixture of distorted corner and edge-sharing FNa3Nb tetrahedra. In the sixth F site, F(6) is bonded to one Na(1), two equivalent Na(3), and one Nb(1) atom to form a mixture of distorted corner and edge-sharing FNa3Nb tetrahedra.