MgYb3 is beta Cu3Ti-like structured and crystallizes in the tetragonal I4/mmm space group. Mg(1) is bonded to four equivalent Yb(1) and eight equivalent Yb(2) atoms to form MgYb12 cuboctahedra that share corners with four equivalent Mg(1)Yb12 cuboctahedra, corners with eight equivalent Yb(1)Yb8Mg4 cuboctahedra, edges with eight equivalent Mg(1)Yb12 cuboctahedra, edges with sixteen equivalent Yb(2)Yb8Mg4 cuboctahedra, faces with four equivalent Mg(1)Yb12 cuboctahedra, faces with six equivalent Yb(1)Yb8Mg4 cuboctahedra, and faces with eight equivalent Yb(2)Yb8Mg4 cuboctahedra. There are two inequivalent Yb sites. In the first Yb site, Yb(1) is bonded to four equivalent Mg(1) and eight equivalent Yb(2) atoms to form YbYb8Mg4 cuboctahedra that share corners with four equivalent Yb(1)Yb8Mg4 cuboctahedra, corners with eight equivalent Mg(1)Yb12 cuboctahedra, edges with eight equivalent Yb(1)Yb8Mg4 cuboctahedra, edges with sixteen equivalent Yb(2)Yb8Mg4 cuboctahedra, faces with four equivalent Yb(1)Yb8Mg4 cuboctahedra, faces with six equivalent Mg(1)Yb12 cuboctahedra, and faces with eight equivalent Yb(2)Yb8Mg4 cuboctahedra. In the second Yb site, Yb(2) is bonded to four equivalent Mg(1), four equivalent Yb(1), and four equivalent Yb(2) atoms to form YbYb8Mg4 cuboctahedra that share corners with twelve equivalent Yb(2)Yb8Mg4 cuboctahedra, edges with eight equivalent Mg(1)Yb12 cuboctahedra, edges with eight equivalent Yb(1)Yb8Mg4 cuboctahedra, edges with eight equivalent Yb(2)Yb8Mg4 cuboctahedra, faces with four equivalent Mg(1)Yb12 cuboctahedra, faces with four equivalent Yb(1)Yb8Mg4 cuboctahedra, and faces with ten equivalent Yb(2)Yb8Mg4 cuboctahedra.
MgYb3 is beta Cu3Ti-like structured and crystallizes in the tetragonal I4/mmm space group. Mg(1) is bonded to four equivalent Yb(1) and eight equivalent Yb(2) atoms to form MgYb12 cuboctahedra that share corners with four equivalent Mg(1)Yb12 cuboctahedra, corners with eight equivalent Yb(1)Yb8Mg4 cuboctahedra, edges with eight equivalent Mg(1)Yb12 cuboctahedra, edges with sixteen equivalent Yb(2)Yb8Mg4 cuboctahedra, faces with four equivalent Mg(1)Yb12 cuboctahedra, faces with six equivalent Yb(1)Yb8Mg4 cuboctahedra, and faces with eight equivalent Yb(2)Yb8Mg4 cuboctahedra. All Mg(1)-Yb(1) bond lengths are 3.68 Å. All Mg(1)-Yb(2) bond lengths are 3.69 Å. There are two inequivalent Yb sites. In the first Yb site, Yb(1) is bonded to four equivalent Mg(1) and eight equivalent Yb(2) atoms to form YbYb8Mg4 cuboctahedra that share corners with four equivalent Yb(1)Yb8Mg4 cuboctahedra, corners with eight equivalent Mg(1)Yb12 cuboctahedra, edges with eight equivalent Yb(1)Yb8Mg4 cuboctahedra, edges with sixteen equivalent Yb(2)Yb8Mg4 cuboctahedra, faces with four equivalent Yb(1)Yb8Mg4 cuboctahedra, faces with six equivalent Mg(1)Yb12 cuboctahedra, and faces with eight equivalent Yb(2)Yb8Mg4 cuboctahedra. All Yb(1)-Yb(2) bond lengths are 3.69 Å. In the second Yb site, Yb(2) is bonded to four equivalent Mg(1), four equivalent Yb(1), and four equivalent Yb(2) atoms to form YbYb8Mg4 cuboctahedra that share corners with twelve equivalent Yb(2)Yb8Mg4 cuboctahedra, edges with eight equivalent Mg(1)Yb12 cuboctahedra, edges with eight equivalent Yb(1)Yb8Mg4 cuboctahedra, edges with eight equivalent Yb(2)Yb8Mg4 cuboctahedra, faces with four equivalent Mg(1)Yb12 cuboctahedra, faces with four equivalent Yb(1)Yb8Mg4 cuboctahedra, and faces with ten equivalent Yb(2)Yb8Mg4 cuboctahedra. All Yb(2)-Yb(2) bond lengths are 3.68 Å.