HoGd3 is alpha La-derived structured and crystallizes in the tetragonal I4/mmm space group. Ho(1) is bonded to four equivalent Gd(2) and eight equivalent Gd(1) atoms to form HoGd12 cuboctahedra that share corners with four equivalent Ho(1)Gd12 cuboctahedra, corners with eight equivalent Gd(2)Gd8Ho4 cuboctahedra, edges with eight equivalent Ho(1)Gd12 cuboctahedra, edges with sixteen equivalent Gd(1)Gd8Ho4 cuboctahedra, faces with four equivalent Ho(1)Gd12 cuboctahedra, faces with six equivalent Gd(2)Gd8Ho4 cuboctahedra, and faces with eight equivalent Gd(1)Gd8Ho4 cuboctahedra. There are two inequivalent Gd sites. In the first Gd site, Gd(1) is bonded to four equivalent Ho(1), four equivalent Gd(1), and four equivalent Gd(2) atoms to form GdGd8Ho4 cuboctahedra that share corners with twelve equivalent Gd(1)Gd8Ho4 cuboctahedra, edges with eight equivalent Ho(1)Gd12 cuboctahedra, edges with eight equivalent Gd(1)Gd8Ho4 cuboctahedra, edges with eight equivalent Gd(2)Gd8Ho4 cuboctahedra, faces with four equivalent Ho(1)Gd12 cuboctahedra, faces with four equivalent Gd(2)Gd8Ho4 cuboctahedra, and faces with ten equivalent Gd(1)Gd8Ho4 cuboctahedra. In the second Gd site, Gd(2) is bonded to four equivalent Ho(1) and eight equivalent Gd(1) atoms to form GdGd8Ho4 cuboctahedra that share corners with four equivalent Gd(2)Gd8Ho4 cuboctahedra, corners with eight equivalent Ho(1)Gd12 cuboctahedra, edges with eight equivalent Gd(2)Gd8Ho4 cuboctahedra, edges with sixteen equivalent Gd(1)Gd8Ho4 cuboctahedra, faces with four equivalent Gd(2)Gd8Ho4 cuboctahedra, faces with six equivalent Ho(1)Gd12 cuboctahedra, and faces with eight equivalent Gd(1)Gd8Ho4 cuboctahedra.
HoGd3 is alpha La-derived structured and crystallizes in the tetragonal I4/mmm space group. Ho(1) is bonded to four equivalent Gd(2) and eight equivalent Gd(1) atoms to form HoGd12 cuboctahedra that share corners with four equivalent Ho(1)Gd12 cuboctahedra, corners with eight equivalent Gd(2)Gd8Ho4 cuboctahedra, edges with eight equivalent Ho(1)Gd12 cuboctahedra, edges with sixteen equivalent Gd(1)Gd8Ho4 cuboctahedra, faces with four equivalent Ho(1)Gd12 cuboctahedra, faces with six equivalent Gd(2)Gd8Ho4 cuboctahedra, and faces with eight equivalent Gd(1)Gd8Ho4 cuboctahedra. All Ho(1)-Gd(2) bond lengths are 3.58 Å. All Ho(1)-Gd(1) bond lengths are 3.59 Å. There are two inequivalent Gd sites. In the first Gd site, Gd(1) is bonded to four equivalent Ho(1), four equivalent Gd(1), and four equivalent Gd(2) atoms to form GdGd8Ho4 cuboctahedra that share corners with twelve equivalent Gd(1)Gd8Ho4 cuboctahedra, edges with eight equivalent Ho(1)Gd12 cuboctahedra, edges with eight equivalent Gd(1)Gd8Ho4 cuboctahedra, edges with eight equivalent Gd(2)Gd8Ho4 cuboctahedra, faces with four equivalent Ho(1)Gd12 cuboctahedra, faces with four equivalent Gd(2)Gd8Ho4 cuboctahedra, and faces with ten equivalent Gd(1)Gd8Ho4 cuboctahedra. All Gd(1)-Gd(1) bond lengths are 3.58 Å. All Gd(1)-Gd(2) bond lengths are 3.59 Å. In the second Gd site, Gd(2) is bonded to four equivalent Ho(1) and eight equivalent Gd(1) atoms to form GdGd8Ho4 cuboctahedra that share corners with four equivalent Gd(2)Gd8Ho4 cuboctahedra, corners with eight equivalent Ho(1)Gd12 cuboctahedra, edges with eight equivalent Gd(2)Gd8Ho4 cuboctahedra, edges with sixteen equivalent Gd(1)Gd8Ho4 cuboctahedra, faces with four equivalent Gd(2)Gd8Ho4 cuboctahedra, faces with six equivalent Ho(1)Gd12 cuboctahedra, and faces with eight equivalent Gd(1)Gd8Ho4 cuboctahedra.