Rb4CdBr6 crystallizes in the trigonal R-3c space group. There are two inequivalent Rb sites. In the first Rb site, Rb(1) is bonded in a 8-coordinate geometry to eight equivalent Br(1) atoms. In the second Rb site, Rb(2) is bonded in a 6-coordinate geometry to six equivalent Br(1) atoms. Cd(1) is bonded in an octahedral geometry to six equivalent Br(1) atoms. Br(1) is bonded to one Rb(2), four equivalent Rb(1), and one Cd(1) atom to form a mixture of distorted edge, face, and corner-sharing BrRb5Cd octahedra. The corner-sharing octahedral tilt angles range from 0-64°.
Rb4CdBr6 crystallizes in the trigonal R-3c space group. There are two inequivalent Rb sites. In the first Rb site, Rb(1) is bonded in a 8-coordinate geometry to eight equivalent Br(1) atoms. There are a spread of Rb(1)-Br(1) bond distances ranging from 3.50-3.65 Å. In the second Rb site, Rb(2) is bonded in a 6-coordinate geometry to six equivalent Br(1) atoms. All Rb(2)-Br(1) bond lengths are 3.37 Å. Cd(1) is bonded in an octahedral geometry to six equivalent Br(1) atoms. All Cd(1)-Br(1) bond lengths are 2.82 Å. Br(1) is bonded to one Rb(2), four equivalent Rb(1), and one Cd(1) atom to form a mixture of distorted edge, face, and corner-sharing BrRb5Cd octahedra. The corner-sharing octahedral tilt angles range from 0-64°.