RbTlCl3 crystallizes in the cubic Fm-3m space group. Rb(1) is bonded to twelve equivalent Cl(1) atoms to form distorted RbCl12 cuboctahedra that share corners with twelve equivalent Rb(1)Cl12 cuboctahedra, faces with six equivalent Rb(1)Cl12 cuboctahedra, faces with four equivalent Tl(1)Cl6 octahedra, and faces with four equivalent Tl(2)Cl6 octahedra. There are two inequivalent Tl sites. In the first Tl site, Tl(1) is bonded to six equivalent Cl(1) atoms to form TlCl6 octahedra that share corners with six equivalent Tl(2)Cl6 octahedra and faces with eight equivalent Rb(1)Cl12 cuboctahedra. The corner-sharing octahedra are not tilted. In the second Tl site, Tl(2) is bonded to six equivalent Cl(1) atoms to form TlCl6 octahedra that share corners with six equivalent Tl(1)Cl6 octahedra and faces with eight equivalent Rb(1)Cl12 cuboctahedra. The corner-sharing octahedra are not tilted. Cl(1) is bonded in a linear geometry to four equivalent Rb(1), one Tl(1), and one Tl(2) atom.
RbTlCl3 crystallizes in the cubic Fm-3m space group. Rb(1) is bonded to twelve equivalent Cl(1) atoms to form distorted RbCl12 cuboctahedra that share corners with twelve equivalent Rb(1)Cl12 cuboctahedra, faces with six equivalent Rb(1)Cl12 cuboctahedra, faces with four equivalent Tl(1)Cl6 octahedra, and faces with four equivalent Tl(2)Cl6 octahedra. All Rb(1)-Cl(1) bond lengths are 3.99 Å. There are two inequivalent Tl sites. In the first Tl site, Tl(1) is bonded to six equivalent Cl(1) atoms to form TlCl6 octahedra that share corners with six equivalent Tl(2)Cl6 octahedra and faces with eight equivalent Rb(1)Cl12 cuboctahedra. The corner-sharing octahedra are not tilted. All Tl(1)-Cl(1) bond lengths are 3.00 Å. In the second Tl site, Tl(2) is bonded to six equivalent Cl(1) atoms to form TlCl6 octahedra that share corners with six equivalent Tl(1)Cl6 octahedra and faces with eight equivalent Rb(1)Cl12 cuboctahedra. The corner-sharing octahedra are not tilted. All Tl(2)-Cl(1) bond lengths are 2.64 Å. Cl(1) is bonded in a linear geometry to four equivalent Rb(1), one Tl(1), and one Tl(2) atom.