DOE OSTI2020
KYb3 is beta Cu3Ti-like structured and crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. K is bonded to twelve Yb atoms to form KYb12 cuboctahedra that share corners with four equivalent KYb12 cuboctahedra, corners with eight equivalent YbK4Yb8 cuboctahedra, edges with eight equivalent KYb12 cuboctahedra, edges with sixteen equivalent YbK4Yb8 cuboctahedra, faces with four equivalent KYb12 cuboctahedra, and faces with fourteen YbK4Yb8 cuboctahedra. There are four shorter (4.03 Å) and eight longer (4.07 Å) K–Yb bond lengths. There are two inequivalent Yb sites. In the first Yb site, Yb is bonded to four equivalent K and eight Yb atoms to form YbK4Yb8 cuboctahedra that share corners with twelve equivalent YbK4Yb8 cuboctahedra, edges with eight equivalent KYb12 cuboctahedra, edges with sixteen YbK4Yb8 cuboctahedra, faces with four equivalent KYb12 cuboctahedra, and faces with fourteen YbK4Yb8 cuboctahedra. There are four shorter (4.03 Å) and four longer (4.07 Å) Yb–Yb bond lengths. In the second Yb site, Yb is bonded to four equivalent K and eight equivalent Yb atoms to form YbK4Yb8 cuboctahedra that share corners with four equivalent YbK4Yb8 cuboctahedra, corners with eight equivalent KYb12 cuboctahedra, edges with twenty-four YbK4Yb8 cuboctahedra, faces with six equivalent KYb12 cuboctahedra, and faces with twelve YbK4Yb8 cuboctahedra.