Rb3AlBr6 is (Cubic) Perovskite-like structured and 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 Br(1) atoms to form distorted RbBr12 cuboctahedra that share corners with twelve equivalent Rb(1)Br12 cuboctahedra, faces with six equivalent Rb(1)Br12 cuboctahedra, faces with four equivalent Rb(2)Br6 octahedra, and faces with four equivalent Al(1)Br6 octahedra. In the second Rb site, Rb(2) is bonded to six equivalent Br(1) atoms to form RbBr6 octahedra that share corners with six equivalent Al(1)Br6 octahedra and faces with eight equivalent Rb(1)Br12 cuboctahedra. The corner-sharing octahedra are not tilted. Al(1) is bonded to six equivalent Br(1) atoms to form AlBr6 octahedra that share corners with six equivalent Rb(2)Br6 octahedra and faces with eight equivalent Rb(1)Br12 cuboctahedra. The corner-sharing octahedra are not tilted. Br(1) is bonded in a distorted linear geometry to one Rb(2), four equivalent Rb(1), and one Al(1) atom.
Rb3AlBr6 is (Cubic) Perovskite-like structured and 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 Br(1) atoms to form distorted RbBr12 cuboctahedra that share corners with twelve equivalent Rb(1)Br12 cuboctahedra, faces with six equivalent Rb(1)Br12 cuboctahedra, faces with four equivalent Rb(2)Br6 octahedra, and faces with four equivalent Al(1)Br6 octahedra. All Rb(1)-Br(1) bond lengths are 4.09 Å. In the second Rb site, Rb(2) is bonded to six equivalent Br(1) atoms to form RbBr6 octahedra that share corners with six equivalent Al(1)Br6 octahedra and faces with eight equivalent Rb(1)Br12 cuboctahedra. The corner-sharing octahedra are not tilted. All Rb(2)-Br(1) bond lengths are 3.24 Å. Al(1) is bonded to six equivalent Br(1) atoms to form AlBr6 octahedra that share corners with six equivalent Rb(2)Br6 octahedra and faces with eight equivalent Rb(1)Br12 cuboctahedra. The corner-sharing octahedra are not tilted. All Al(1)-Br(1) bond lengths are 2.52 Å. Br(1) is bonded in a distorted linear geometry to one Rb(2), four equivalent Rb(1), and one Al(1) atom.