DOE OSTI2020
Rb3Tl is beta-derived structured and crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. there are two inequivalent Rb sites. In the first Rb site, Rb is bonded to eight Rb and four equivalent Tl atoms to form distorted RbRb8Tl4 cuboctahedra that share corners with twelve equivalent RbRb8Tl4 cuboctahedra, edges with eight equivalent TlRb12 cuboctahedra, edges with sixteen RbRb8Tl4 cuboctahedra, faces with four equivalent TlRb12 cuboctahedra, and faces with fourteen RbRb8Tl4 cuboctahedra. There are four shorter (4.39 Å) and four longer (4.43 Å) Rb–Rb bond lengths. All Rb–Tl bond lengths are 4.43 Å. In the second Rb site, Rb is bonded to eight equivalent Rb and four equivalent Tl atoms to form distorted RbRb8Tl4 cuboctahedra that share corners with four equivalent RbRb8Tl4 cuboctahedra, corners with eight equivalent TlRb12 cuboctahedra, edges with twenty-four RbRb8Tl4 cuboctahedra, faces with six equivalent TlRb12 cuboctahedra, and faces with twelve RbRb8Tl4 cuboctahedra. All Rb–Tl bond lengths are 4.39 Å. Tl is bonded to twelve Rb atoms to form distorted TlRb12 cuboctahedra that share corners with four equivalent TlRb12 cuboctahedra, corners with eight equivalent RbRb8Tl4 cuboctahedra, edges with eight equivalent TlRb12 cuboctahedra, edges with sixteen equivalent RbRb8Tl4 cuboctahedra, faces with four equivalent TlRb12 cuboctahedra, and faces with fourteen RbRb8Tl4 cuboctahedra.