Rb3AlF6 crystallizes in the cubic Fm-3m space group. There are two inequivalent Rb sites. In the first Rb site, Rb(1) is bonded to twelve equivalent F(1) atoms to form distorted RbF12 cuboctahedra that share corners with twelve equivalent Rb(1)F12 cuboctahedra, faces with six equivalent Rb(1)F12 cuboctahedra, faces with four equivalent Rb(2)F6 octahedra, and faces with four equivalent Al(1)F6 octahedra. In the second Rb site, Rb(2) is bonded to six equivalent F(1) atoms to form RbF6 octahedra that share corners with six equivalent Al(1)F6 octahedra and faces with eight equivalent Rb(1)F12 cuboctahedra. The corner-sharing octahedra are not tilted. Al(1) is bonded to six equivalent F(1) atoms to form AlF6 octahedra that share corners with six equivalent Rb(2)F6 octahedra and faces with eight equivalent Rb(1)F12 cuboctahedra. The corner-sharing octahedra are not tilted. F(1) is bonded in a 1-coordinate geometry to one Rb(2), four equivalent Rb(1), and one Al(1) atom.
Rb3AlF6 crystallizes in the cubic Fm-3m space group. There are two inequivalent Rb sites. In the first Rb site, Rb(1) is bonded to twelve equivalent F(1) atoms to form distorted RbF12 cuboctahedra that share corners with twelve equivalent Rb(1)F12 cuboctahedra, faces with six equivalent Rb(1)F12 cuboctahedra, faces with four equivalent Rb(2)F6 octahedra, and faces with four equivalent Al(1)F6 octahedra. All Rb(1)-F(1) bond lengths are 3.15 Å. In the second Rb site, Rb(2) is bonded to six equivalent F(1) atoms to form RbF6 octahedra that share corners with six equivalent Al(1)F6 octahedra and faces with eight equivalent Rb(1)F12 cuboctahedra. The corner-sharing octahedra are not tilted. All Rb(2)-F(1) bond lengths are 2.61 Å. Al(1) is bonded to six equivalent F(1) atoms to form AlF6 octahedra that share corners with six equivalent Rb(2)F6 octahedra and faces with eight equivalent Rb(1)F12 cuboctahedra. The corner-sharing octahedra are not tilted. All Al(1)-F(1) bond lengths are 1.81 Å. F(1) is bonded in a 1-coordinate geometry to one Rb(2), four equivalent Rb(1), and one Al(1) atom.