Ho2(CoNi)5 crystallizes in the orthorhombic Pmmm space group. There are two inequivalent Ho sites. In the first Ho site, Ho(1) is bonded in a 18-coordinate geometry to two equivalent Co(1), four equivalent Co(2), four equivalent Ni(1), and eight equivalent Ni(2) atoms. In the second Ho site, Ho(2) is bonded in a 18-coordinate geometry to two equivalent Co(2), four equivalent Co(1), four equivalent Co(3), and eight equivalent Ni(2) atoms. There are three inequivalent Co sites. In the first Co site, Co(1) is bonded in a 9-coordinate geometry to one Ho(1), two equivalent Ho(2), two equivalent Co(3), and four equivalent Ni(2) atoms. In the second Co site, Co(2) is bonded in a 9-coordinate geometry to one Ho(2), two equivalent Ho(1), two equivalent Ni(1), and four equivalent Ni(2) atoms. In the third Co site, Co(3) is bonded to four equivalent Ho(2), four equivalent Co(1), and four equivalent Ni(2) atoms to form CoHo4Co4Ni4 cuboctahedra that share corners with four equivalent Co(3)Ho4Co4Ni4 cuboctahedra, corners with four equivalent Ni(1)Ho4Co4Ni4 cuboctahedra, corners with eight equivalent Ni(2)Ho4Co5Ni3 cuboctahedra, edges with two equivalent Co(3)Ho4Co4Ni4 cuboctahedra, edges with eight equivalent Ni(2)Ho4Co5Ni3 cuboctahedra, faces with two equivalent Co(3)Ho4Co4Ni4 cuboctahedra, and faces with eight equivalent Ni(2)Ho4Co5Ni3 cuboctahedra. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to four equivalent Ho(1), four equivalent Co(2), and four equivalent Ni(2) atoms to form NiHo4Co4Ni4 cuboctahedra that share corners with four equivalent Co(3)Ho4Co4Ni4 cuboctahedra, corners with four equivalent Ni(1)Ho4Co4Ni4 cuboctahedra, corners with eight equivalent Ni(2)Ho4Co5Ni3 cuboctahedra, edges with two equivalent Ni(1)Ho4Co4Ni4 cuboctahedra, edges with eight equivalent Ni(2)Ho4Co5Ni3 cuboctahedra, faces with two equivalent Ni(1)Ho4Co4Ni4 cuboctahedra, and faces with eight equivalent Ni(2)Ho4Co5Ni3 cuboctahedra. In the second Ni site, Ni(2) is bonded to two equivalent Ho(1), two equivalent Ho(2), one Co(3), two equivalent Co(1), two equivalent Co(2), one Ni(1), and two equivalent Ni(2) atoms to form NiHo4Co5Ni3 cuboctahedra that share corners with two equivalent Co(3)Ho4Co4Ni4 cuboctahedra, corners with two equivalent Ni(1)Ho4Co4Ni4 cuboctahedra, corners with twelve equivalent Ni(2)Ho4Co5Ni3 cuboctahedra, edges with two equivalent Co(3)Ho4Co4Ni4 cuboctahedra, edges with two equivalent Ni(1)Ho4Co4Ni4 cuboctahedra, edges with six equivalent Ni(2)Ho4Co5Ni3 cuboctahedra, faces with two equivalent Co(3)Ho4Co4Ni4 cuboctahedra, faces with two equivalent Ni(1)Ho4Co4Ni4 cuboctahedra, and faces with six equivalent Ni(2)Ho4Co5Ni3 cuboctahedra.
Ho2(CoNi)5 crystallizes in the orthorhombic Pmmm space group. There are two inequivalent Ho sites. In the first Ho site, Ho(1) is bonded in a 18-coordinate geometry to two equivalent Co(1), four equivalent Co(2), four equivalent Ni(1), and eight equivalent Ni(2) atoms. Both Ho(1)-Co(1) bond lengths are 2.86 Å. All Ho(1)-Co(2) bond lengths are 2.83 Å. All Ho(1)-Ni(1) bond lengths are 3.15 Å. All Ho(1)-Ni(2) bond lengths are 3.14 Å. In the second Ho site, Ho(2) is bonded in a 18-coordinate geometry to two equivalent Co(2), four equivalent Co(1), four equivalent Co(3), and eight equivalent Ni(2) atoms. Both Ho(2)-Co(2) bond lengths are 2.82 Å. All Ho(2)-Co(1) bond lengths are 2.81 Å. All Ho(2)-Co(3) bond lengths are 3.15 Å. All Ho(2)-Ni(2) bond lengths are 3.14 Å. There are three inequivalent Co sites. In the first Co site, Co(1) is bonded in a 9-coordinate geometry to one Ho(1), two equivalent Ho(2), two equivalent Co(3), and four equivalent Ni(2) atoms. Both Co(1)-Co(3) bond lengths are 2.40 Å. All Co(1)-Ni(2) bond lengths are 2.44 Å. In the second Co site, Co(2) is bonded in a 9-coordinate geometry to one Ho(2), two equivalent Ho(1), two equivalent Ni(1), and four equivalent Ni(2) atoms. Both Co(2)-Ni(1) bond lengths are 2.43 Å. All Co(2)-Ni(2) bond lengths are 2.42 Å. In the third Co site, Co(3) is bonded to four equivalent Ho(2), four equivalent Co(1), and four equivalent Ni(2) atoms to form CoHo4Co4Ni4 cuboctahedra that share corners with four equivalent Co(3)Ho4Co4Ni4 cuboctahedra, corners with four equivalent Ni(1)Ho4Co4Ni4 cuboctahedra, corners with eight equivalent Ni(2)Ho4Co5Ni3 cuboctahedra, edges with two equivalent Co(3)Ho4Co4Ni4 cuboctahedra, edges with eight equivalent Ni(2)Ho4Co5Ni3 cuboctahedra, faces with two equivalent Co(3)Ho4Co4Ni4 cuboctahedra, and faces with eight equivalent Ni(2)Ho4Co5Ni3 cuboctahedra. All Co(3)-Ni(2) bond lengths are 2.45 Å. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to four equivalent Ho(1), four equivalent Co(2), and four equivalent Ni(2) atoms to form NiHo4Co4Ni4 cuboctahedra that share corners with four equivalent Co(3)Ho4Co4Ni4 cuboctahedra, corners with four equivalent Ni(1)Ho4Co4Ni4 cuboctahedra, corners with eight equivalent Ni(2)Ho4Co5Ni3 cuboctahedra, edges with two equivalent Ni(1)Ho4Co4Ni4 cuboctahedra, edges with eight equivalent Ni(2)Ho4Co5Ni3 cuboctahedra, faces with two equivalent Ni(1)Ho4Co4Ni4 cuboctahedra, and faces with eight equivalent Ni(2)Ho4Co5Ni3 cuboctahedra. All Ni(1)-Ni(2) bond lengths are 2.45 Å. In the second Ni site, Ni(2) is bonded to two equivalent Ho(1), two equivalent Ho(2), one Co(3), two equivalent Co(1), two equivalent Co(2), one Ni(1), and two equivalent Ni(2) atoms to form NiHo4Co5Ni3 cuboctahedra that share corners with two equivalent Co(3)Ho4Co4Ni4 cuboctahedra, corners with two equivalent Ni(1)Ho4Co4Ni4 cuboctahedra, corners with twelve equivalent Ni(2)Ho4Co5Ni3 cuboctahedra, edges with two equivalent Co(3)Ho4Co4Ni4 cuboctahedra, edges with two equivalent Ni(1)Ho4Co4Ni4 cuboctahedra, edges with six equivalent Ni(2)Ho4Co5Ni3 cuboctahedra, faces with two equivalent Co(3)Ho4Co4Ni4 cuboctahedra, faces with two equivalent Ni(1)Ho4Co4Ni4 cuboctahedra, and faces with six equivalent Ni(2)Ho4Co5Ni3 cuboctahedra. There is one shorter (2.44 Å) and one longer (2.46 Å) Ni(2)-Ni(2) bond length.