CsBe2F5 crystallizes in the cubic P4_132 space group. Cs(1) is bonded to six equivalent F(1) and six equivalent F(2) atoms to form CsF12 cuboctahedra that share corners with twelve equivalent Be(1)F4 tetrahedra, faces with six equivalent Cs(1)F12 cuboctahedra, and faces with two equivalent Be(1)F4 tetrahedra. Be(1) is bonded to one F(2) and three equivalent F(1) atoms to form BeF4 tetrahedra that share corners with six equivalent Cs(1)F12 cuboctahedra, corners with three equivalent Be(1)F4 tetrahedra, and  a faceface with one Cs(1)F12 cuboctahedra. There are two inequivalent F sites. In the first F site, F(2) is bonded in a single-bond geometry to three equivalent Cs(1) and one Be(1) atom. In the second F site, F(1) is bonded in a bent 120 degrees geometry to two equivalent Cs(1) and two equivalent Be(1) atoms.
CsBe2F5 crystallizes in the cubic P4_132 space group. Cs(1) is bonded to six equivalent F(1) and six equivalent F(2) atoms to form CsF12 cuboctahedra that share corners with twelve equivalent Be(1)F4 tetrahedra, faces with six equivalent Cs(1)F12 cuboctahedra, and faces with two equivalent Be(1)F4 tetrahedra. All Cs(1)-F(1) bond lengths are 3.35 Å. All Cs(1)-F(2) bond lengths are 3.23 Å. Be(1) is bonded to one F(2) and three equivalent F(1) atoms to form BeF4 tetrahedra that share corners with six equivalent Cs(1)F12 cuboctahedra, corners with three equivalent Be(1)F4 tetrahedra, and  a faceface with one Cs(1)F12 cuboctahedra. The Be(1)-F(2) bond length is 1.49 Å. All Be(1)-F(1) bond lengths are 1.57 Å. There are two inequivalent F sites. In the first F site, F(2) is bonded in a single-bond geometry to three equivalent Cs(1) and one Be(1) atom. In the second F site, F(1) is bonded in a bent 120 degrees geometry to two equivalent Cs(1) and two equivalent Be(1) atoms.