Rb8BeZr6Br20 crystallizes in the cubic Fm-3m space group. Rb(1) is bonded in a 4-coordinate geometry to one Br(3) and three equivalent Br(2) atoms. Be(1) is bonded to six equivalent Zr(1) atoms to form BeZr6 octahedra that share corners with six equivalent Br(2)Rb4Zr trigonal bipyramids. Zr(1) is bonded to one Be(1), one Br(2), and four equivalent Br(1) atoms to form a mixture of edge and corner-sharing ZrBeBr5 octahedra. The corner-sharing octahedra are not tilted. There are three inequivalent Br sites. In the first Br site, Br(2) is bonded to four equivalent Rb(1) and one Zr(1) atom to form distorted BrRb4Zr trigonal bipyramids that share  a cornercorner with one Be(1)Zr6 octahedra, corners with four equivalent Br(3)Rb4 tetrahedra, and edges with four equivalent Br(2)Rb4Zr trigonal bipyramids. The corner-sharing octahedra are not tilted. In the second Br site, Br(3) is bonded to four equivalent Rb(1) atoms to form corner-sharing BrRb4 tetrahedra. In the third Br site, Br(1) is bonded in a distorted L-shaped geometry to two equivalent Zr(1) atoms.
Rb8BeZr6Br20 crystallizes in the cubic Fm-3m space group. Rb(1) is bonded in a 4-coordinate geometry to one Br(3) and three equivalent Br(2) atoms. The Rb(1)-Br(3) bond length is 3.27 Å. All Rb(1)-Br(2) bond lengths are 3.46 Å. Be(1) is bonded to six equivalent Zr(1) atoms to form BeZr6 octahedra that share corners with six equivalent Br(2)Rb4Zr trigonal bipyramids. All Be(1)-Zr(1) bond lengths are 2.40 Å. Zr(1) is bonded to one Be(1), one Br(2), and four equivalent Br(1) atoms to form a mixture of edge and corner-sharing ZrBeBr5 octahedra. The corner-sharing octahedra are not tilted. The Zr(1)-Br(2) bond length is 2.92 Å. All Zr(1)-Br(1) bond lengths are 2.75 Å. There are three inequivalent Br sites. In the first Br site, Br(2) is bonded to four equivalent Rb(1) and one Zr(1) atom to form distorted BrRb4Zr trigonal bipyramids that share  a cornercorner with one Be(1)Zr6 octahedra, corners with four equivalent Br(3)Rb4 tetrahedra, and edges with four equivalent Br(2)Rb4Zr trigonal bipyramids. The corner-sharing octahedra are not tilted. In the second Br site, Br(3) is bonded to four equivalent Rb(1) atoms to form corner-sharing BrRb4 tetrahedra. In the third Br site, Br(1) is bonded in a distorted L-shaped geometry to two equivalent Zr(1) atoms.