Rb2NaAl3F12 crystallizes in the monoclinic P2_1/m space group. There are two inequivalent Rb sites. In the first Rb site, Rb(1) is bonded in a 7-coordinate geometry to one F(4), two equivalent F(5), and four equivalent F(7) atoms. In the second Rb site, Rb(2) is bonded in a 8-coordinate geometry to one F(2), one F(3), two equivalent F(5), two equivalent F(6), and two equivalent F(8) atoms. Na(1) is bonded to one F(2), one F(4), two equivalent F(5), and two equivalent F(7) atoms to form distorted NaF6 octahedra that share corners with two equivalent Al(1)F6 octahedra, corners with two equivalent Al(2)F6 octahedra, and corners with two equivalent Al(3)F6 octahedra. The corner-sharing octahedral tilt angles range from 50-65°. There are three inequivalent Al sites. In the first Al site, Al(1) is bonded to two equivalent F(1), two equivalent F(5), and two equivalent F(6) atoms to form AlF6 octahedra that share corners with two equivalent Na(1)F6 octahedra, corners with two equivalent Al(1)F6 octahedra, and corners with two equivalent Al(3)F6 octahedra. The corner-sharing octahedral tilt angles range from 35-65°. In the second Al site, Al(2) is bonded to two equivalent F(3), two equivalent F(7), and two equivalent F(8) atoms to form AlF6 octahedra that share corners with two equivalent Na(1)F6 octahedra, corners with two equivalent Al(2)F6 octahedra, and corners with two equivalent Al(3)F6 octahedra. The corner-sharing octahedral tilt angles range from 34-56°. In the third Al site, Al(3) is bonded to one F(2), one F(4), two equivalent F(6), and two equivalent F(8) atoms to form AlF6 octahedra that share corners with two equivalent Na(1)F6 octahedra, corners with two equivalent Al(1)F6 octahedra, and corners with two equivalent Al(2)F6 octahedra. The corner-sharing octahedral tilt angles range from 34-60°. There are eight inequivalent F sites. In the first F site, F(8) is bonded in a bent 150 degrees geometry to one Rb(2), one Al(2), and one Al(3) atom. In the second F site, F(1) is bonded in a bent 150 degrees geometry to two equivalent Al(1) atoms. In the third F site, F(2) is bonded in a distorted trigonal planar geometry to one Rb(2), one Na(1), and one Al(3) atom. In the fourth F site, F(3) is bonded in a distorted bent 150 degrees geometry to one Rb(2) and two equivalent Al(2) atoms. In the fifth F site, F(4) is bonded in a 2-coordinate geometry to one Rb(1), one Na(1), and one Al(3) atom. In the sixth F site, F(5) is bonded in a 4-coordinate geometry to one Rb(1), one Rb(2), one Na(1), and one Al(1) atom. In the seventh F site, F(6) is bonded in a bent 150 degrees geometry to one Rb(2), one Al(1), and one Al(3) atom. In the eighth F site, F(7) is bonded in a 4-coordinate geometry to two equivalent Rb(1), one Na(1), and one Al(2) atom.
Rb2NaAl3F12 crystallizes in the monoclinic P2_1/m space group. There are two inequivalent Rb sites. In the first Rb site, Rb(1) is bonded in a 7-coordinate geometry to one F(4), two equivalent F(5), and four equivalent F(7) atoms. The Rb(1)-F(4) bond length is 3.03 Å. Both Rb(1)-F(5) bond lengths are 3.08 Å. There are two shorter (2.92 Å) and two longer (3.09 Å) Rb(1)-F(7) bond lengths. In the second Rb site, Rb(2) is bonded in a 8-coordinate geometry to one F(2), one F(3), two equivalent F(5), two equivalent F(6), and two equivalent F(8) atoms. The Rb(2)-F(2) bond length is 2.78 Å. The Rb(2)-F(3) bond length is 3.07 Å. Both Rb(2)-F(5) bond lengths are 2.87 Å. Both Rb(2)-F(6) bond lengths are 3.22 Å. Both Rb(2)-F(8) bond lengths are 3.13 Å. Na(1) is bonded to one F(2), one F(4), two equivalent F(5), and two equivalent F(7) atoms to form distorted NaF6 octahedra that share corners with two equivalent Al(1)F6 octahedra, corners with two equivalent Al(2)F6 octahedra, and corners with two equivalent Al(3)F6 octahedra. The corner-sharing octahedral tilt angles range from 50-65°. The Na(1)-F(2) bond length is 2.32 Å. The Na(1)-F(4) bond length is 2.28 Å. Both Na(1)-F(5) bond lengths are 2.38 Å. Both Na(1)-F(7) bond lengths are 2.37 Å. There are three inequivalent Al sites. In the first Al site, Al(1) is bonded to two equivalent F(1), two equivalent F(5), and two equivalent F(6) atoms to form AlF6 octahedra that share corners with two equivalent Na(1)F6 octahedra, corners with two equivalent Al(1)F6 octahedra, and corners with two equivalent Al(3)F6 octahedra. The corner-sharing octahedral tilt angles range from 35-65°. Both Al(1)-F(1) bond lengths are 1.86 Å. Both Al(1)-F(5) bond lengths are 1.77 Å. Both Al(1)-F(6) bond lengths are 1.87 Å. In the second Al site, Al(2) is bonded to two equivalent F(3), two equivalent F(7), and two equivalent F(8) atoms to form AlF6 octahedra that share corners with two equivalent Na(1)F6 octahedra, corners with two equivalent Al(2)F6 octahedra, and corners with two equivalent Al(3)F6 octahedra. The corner-sharing octahedral tilt angles range from 34-56°. Both Al(2)-F(3) bond lengths are 1.87 Å. Both Al(2)-F(7) bond lengths are 1.78 Å. Both Al(2)-F(8) bond lengths are 1.86 Å. In the third Al site, Al(3) is bonded to one F(2), one F(4), two equivalent F(6), and two equivalent F(8) atoms to form AlF6 octahedra that share corners with two equivalent Na(1)F6 octahedra, corners with two equivalent Al(1)F6 octahedra, and corners with two equivalent Al(2)F6 octahedra. The corner-sharing octahedral tilt angles range from 34-60°. The Al(3)-F(2) bond length is 1.78 Å. The Al(3)-F(4) bond length is 1.76 Å. Both Al(3)-F(6) bond lengths are 1.86 Å. Both Al(3)-F(8) bond lengths are 1.87 Å. There are eight inequivalent F sites. In the first F site, F(8) is bonded in a bent 150 degrees geometry to one Rb(2), one Al(2), and one Al(3) atom. In the second F site, F(1) is bonded in a bent 150 degrees geometry to two equivalent Al(1) atoms. In the third F site, F(2) is bonded in a distorted trigonal planar geometry to one Rb(2), one Na(1), and one Al(3) atom. In the fourth F site, F(3) is bonded in a distorted bent 150 degrees geometry to one Rb(2) and two equivalent Al(2) atoms. In the fifth F site, F(4) is bonded in a 2-coordinate geometry to one Rb(1), one Na(1), and one Al(3) atom. In the sixth F site, F(5) is bonded in a 4-coordinate geometry to one Rb(1), one Rb(2), one Na(1), and one Al(1) atom. In the seventh F site, F(6) is bonded in a bent 150 degrees geometry to one Rb(2), one Al(1), and one Al(3) atom. In the eighth F site, F(7) is bonded in a 4-coordinate geometry to two equivalent Rb(1), one Na(1), and one Al(2) atom.