Rb2HgAsBr6 is (Cubic) Perovskite-derived structured and crystallizes in the cubic Fm-3m space group. Rb(1) is bonded to twelve equivalent Br(1) atoms to form RbBr12 cuboctahedra that share corners with twelve equivalent Rb(1)Br12 cuboctahedra, faces with six equivalent Rb(1)Br12 cuboctahedra, faces with four equivalent Hg(1)Br6 octahedra, and faces with four equivalent As(1)Br6 octahedra. Hg(1) is bonded to six equivalent Br(1) atoms to form HgBr6 octahedra that share corners with six equivalent As(1)Br6 octahedra and faces with eight equivalent Rb(1)Br12 cuboctahedra. The corner-sharing octahedra are not tilted. As(1) is bonded to six equivalent Br(1) atoms to form AsBr6 octahedra that share corners with six equivalent Hg(1)Br6 octahedra and faces with eight equivalent Rb(1)Br12 cuboctahedra. The corner-sharing octahedra are not tilted. Br(1) is bonded to four equivalent Rb(1), one Hg(1), and one As(1) atom to form a mixture of distorted corner, face, and edge-sharing BrRb4HgAs octahedra. The corner-sharing octahedral tilt angles range from 0-60°.
Rb2HgAsBr6 is (Cubic) Perovskite-derived structured and crystallizes in the cubic Fm-3m space group. Rb(1) is bonded to twelve equivalent Br(1) atoms to form RbBr12 cuboctahedra that share corners with twelve equivalent Rb(1)Br12 cuboctahedra, faces with six equivalent Rb(1)Br12 cuboctahedra, faces with four equivalent Hg(1)Br6 octahedra, and faces with four equivalent As(1)Br6 octahedra. All Rb(1)-Br(1) bond lengths are 3.98 Å. Hg(1) is bonded to six equivalent Br(1) atoms to form HgBr6 octahedra that share corners with six equivalent As(1)Br6 octahedra and faces with eight equivalent Rb(1)Br12 cuboctahedra. The corner-sharing octahedra are not tilted. All Hg(1)-Br(1) bond lengths are 2.95 Å. As(1) is bonded to six equivalent Br(1) atoms to form AsBr6 octahedra that share corners with six equivalent Hg(1)Br6 octahedra and faces with eight equivalent Rb(1)Br12 cuboctahedra. The corner-sharing octahedra are not tilted. All As(1)-Br(1) bond lengths are 2.68 Å. Br(1) is bonded to four equivalent Rb(1), one Hg(1), and one As(1) atom to form a mixture of distorted corner, face, and edge-sharing BrRb4HgAs octahedra. The corner-sharing octahedral tilt angles range from 0-60°.