Na3AlF6 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a 8-coordinate geometry to two equivalent F(3), three equivalent F(1), and three equivalent F(2) atoms. In the second Na site, Na(2) is bonded to two equivalent F(1), two equivalent F(2), and two equivalent F(3) atoms to form NaF6 octahedra that share corners with six equivalent Al(1)F6 octahedra. The corner-sharing octahedral tilt angles range from 31-38°. Al(1) is bonded to two equivalent F(1), two equivalent F(2), and two equivalent F(3) atoms to form AlF6 octahedra that share corners with six equivalent Na(2)F6 octahedra. The corner-sharing octahedral tilt angles range from 31-38°. There are three inequivalent F sites. In the first F site, F(1) is bonded in a 5-coordinate geometry to one Na(2), three equivalent Na(1), and one Al(1) atom. In the second F site, F(2) is bonded in a 5-coordinate geometry to one Na(2), three equivalent Na(1), and one Al(1) atom. In the third F site, F(3) is bonded in a distorted see-saw-like geometry to one Na(2), two equivalent Na(1), and one Al(1) atom.
Na3AlF6 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a 8-coordinate geometry to two equivalent F(3), three equivalent F(1), and three equivalent F(2) atoms. There is one shorter (2.26 Å) and one longer (2.31 Å) Na(1)-F(3) bond length. There are a spread of Na(1)-F(1) bond distances ranging from 2.28-2.83 Å. There are a spread of Na(1)-F(2) bond distances ranging from 2.28-2.67 Å. In the second Na site, Na(2) is bonded to two equivalent F(1), two equivalent F(2), and two equivalent F(3) atoms to form NaF6 octahedra that share corners with six equivalent Al(1)F6 octahedra. The corner-sharing octahedral tilt angles range from 31-38°. Both Na(2)-F(1) bond lengths are 2.25 Å. Both Na(2)-F(2) bond lengths are 2.19 Å. Both Na(2)-F(3) bond lengths are 2.24 Å. Al(1) is bonded to two equivalent F(1), two equivalent F(2), and two equivalent F(3) atoms to form AlF6 octahedra that share corners with six equivalent Na(2)F6 octahedra. The corner-sharing octahedral tilt angles range from 31-38°. Both Al(1)-F(1) bond lengths are 1.82 Å. Both Al(1)-F(2) bond lengths are 1.81 Å. Both Al(1)-F(3) bond lengths are 1.81 Å. There are three inequivalent F sites. In the first F site, F(1) is bonded in a 5-coordinate geometry to one Na(2), three equivalent Na(1), and one Al(1) atom. In the second F site, F(2) is bonded in a 5-coordinate geometry to one Na(2), three equivalent Na(1), and one Al(1) atom. In the third F site, F(3) is bonded in a distorted see-saw-like geometry to one Na(2), two equivalent Na(1), and one Al(1) atom.