DOE OSTI2020
RbYb3 is beta Cu3Ti-like structured and crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Rb is bonded to twelve Yb atoms to form RbYb12 cuboctahedra that share corners with four equivalent RbYb12 cuboctahedra, corners with eight equivalent YbRb4Yb8 cuboctahedra, edges with eight equivalent RbYb12 cuboctahedra, edges with sixteen equivalent YbRb4Yb8 cuboctahedra, faces with four equivalent RbYb12 cuboctahedra, and faces with fourteen YbRb4Yb8 cuboctahedra. All Rb–Yb bond lengths are 4.12 Å. There are two inequivalent Yb sites. In the first Yb site, Yb is bonded to four equivalent Rb and eight Yb atoms to form YbRb4Yb8 cuboctahedra that share corners with twelve equivalent YbRb4Yb8 cuboctahedra, edges with eight equivalent RbYb12 cuboctahedra, edges with sixteen YbRb4Yb8 cuboctahedra, faces with four equivalent RbYb12 cuboctahedra, and faces with fourteen YbRb4Yb8 cuboctahedra. All Yb–Yb bond lengths are 4.12 Å. In the second Yb site, Yb is bonded to four equivalent Rb and eight equivalent Yb atoms to form YbRb4Yb8 cuboctahedra that share corners with four equivalent YbRb4Yb8 cuboctahedra, corners with eight equivalent RbYb12 cuboctahedra, edges with twenty-four YbRb4Yb8 cuboctahedra, faces with six equivalent RbYb12 cuboctahedra, and faces with twelve YbRb4Yb8 cuboctahedra.