Bi2Rb is Cubic Laves structured and crystallizes in the cubic Fd-3m space group. The structure is three-dimensional. Rb is bonded in a 12-coordinate geometry to twelve equivalent Bi atoms. All Rb–Bi bond lengths are 4.03 Å. Bi is bonded to six equivalent Rb and six equivalent Bi atoms to form a mixture of corner, edge, and face-sharing BiRb6Bi6 cuboctahedra. All Bi–Bi bond lengths are 3.43 Å.