HoCo4Cu crystallizes in the hexagonal P-6m2 space group. Ho(1) is bonded in a distorted hexagonal planar geometry to three equivalent Co(1), twelve equivalent Co(2), and three equivalent Cu(1) atoms. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded to three equivalent Ho(1), six equivalent Co(2), and three equivalent Cu(1) atoms to form distorted CoHo3Co6Cu3 cuboctahedra that share corners with nine equivalent Cu(1)Ho3Co9 cuboctahedra, corners with twelve equivalent Co(2)Ho4Co6Cu2 cuboctahedra, edges with six equivalent Co(1)Ho3Co6Cu3 cuboctahedra, faces with two equivalent Co(1)Ho3Co6Cu3 cuboctahedra, faces with three equivalent Cu(1)Ho3Co9 cuboctahedra, and faces with eighteen equivalent Co(2)Ho4Co6Cu2 cuboctahedra. In the second Co site, Co(2) is bonded to four equivalent Ho(1), two equivalent Co(1), four equivalent Co(2), and two equivalent Cu(1) atoms to form CoHo4Co6Cu2 cuboctahedra that share corners with four equivalent Co(1)Ho3Co6Cu3 cuboctahedra, corners with four equivalent Cu(1)Ho3Co9 cuboctahedra, corners with sixteen equivalent Co(2)Ho4Co6Cu2 cuboctahedra, edges with ten equivalent Co(2)Ho4Co6Cu2 cuboctahedra, faces with six equivalent Co(1)Ho3Co6Cu3 cuboctahedra, faces with six equivalent Cu(1)Ho3Co9 cuboctahedra, and faces with ten equivalent Co(2)Ho4Co6Cu2 cuboctahedra. Cu(1) is bonded to three equivalent Ho(1), three equivalent Co(1), and six equivalent Co(2) atoms to form distorted CuHo3Co9 cuboctahedra that share corners with nine equivalent Co(1)Ho3Co6Cu3 cuboctahedra, corners with twelve equivalent Co(2)Ho4Co6Cu2 cuboctahedra, edges with six equivalent Cu(1)Ho3Co9 cuboctahedra, faces with two equivalent Cu(1)Ho3Co9 cuboctahedra, faces with three equivalent Co(1)Ho3Co6Cu3 cuboctahedra, and faces with eighteen equivalent Co(2)Ho4Co6Cu2 cuboctahedra.
HoCo4Cu crystallizes in the hexagonal P-6m2 space group. Ho(1) is bonded in a distorted hexagonal planar geometry to three equivalent Co(1), twelve equivalent Co(2), and three equivalent Cu(1) atoms. All Ho(1)-Co(1) bond lengths are 2.83 Å. All Ho(1)-Co(2) bond lengths are 3.16 Å. All Ho(1)-Cu(1) bond lengths are 2.83 Å. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded to three equivalent Ho(1), six equivalent Co(2), and three equivalent Cu(1) atoms to form distorted CoHo3Co6Cu3 cuboctahedra that share corners with nine equivalent Cu(1)Ho3Co9 cuboctahedra, corners with twelve equivalent Co(2)Ho4Co6Cu2 cuboctahedra, edges with six equivalent Co(1)Ho3Co6Cu3 cuboctahedra, faces with two equivalent Co(1)Ho3Co6Cu3 cuboctahedra, faces with three equivalent Cu(1)Ho3Co9 cuboctahedra, and faces with eighteen equivalent Co(2)Ho4Co6Cu2 cuboctahedra. All Co(1)-Co(2) bond lengths are 2.44 Å. All Co(1)-Cu(1) bond lengths are 2.83 Å. In the second Co site, Co(2) is bonded to four equivalent Ho(1), two equivalent Co(1), four equivalent Co(2), and two equivalent Cu(1) atoms to form CoHo4Co6Cu2 cuboctahedra that share corners with four equivalent Co(1)Ho3Co6Cu3 cuboctahedra, corners with four equivalent Cu(1)Ho3Co9 cuboctahedra, corners with sixteen equivalent Co(2)Ho4Co6Cu2 cuboctahedra, edges with ten equivalent Co(2)Ho4Co6Cu2 cuboctahedra, faces with six equivalent Co(1)Ho3Co6Cu3 cuboctahedra, faces with six equivalent Cu(1)Ho3Co9 cuboctahedra, and faces with ten equivalent Co(2)Ho4Co6Cu2 cuboctahedra. There are two shorter (2.44 Å) and two longer (2.47 Å) Co(2)-Co(2) bond lengths. Both Co(2)-Cu(1) bond lengths are 2.45 Å. Cu(1) is bonded to three equivalent Ho(1), three equivalent Co(1), and six equivalent Co(2) atoms to form distorted CuHo3Co9 cuboctahedra that share corners with nine equivalent Co(1)Ho3Co6Cu3 cuboctahedra, corners with twelve equivalent Co(2)Ho4Co6Cu2 cuboctahedra, edges with six equivalent Cu(1)Ho3Co9 cuboctahedra, faces with two equivalent Cu(1)Ho3Co9 cuboctahedra, faces with three equivalent Co(1)Ho3Co6Cu3 cuboctahedra, and faces with eighteen equivalent Co(2)Ho4Co6Cu2 cuboctahedra.