Ho4Ni13C4 crystallizes in the orthorhombic Cmmm space group. There are two inequivalent Ho sites. In the first Ho site, Ho(1) is bonded in a 15-coordinate geometry to one Ni(5), two equivalent Ni(3), four equivalent Ni(2), four equivalent Ni(4), and four equivalent C(1) atoms. In the second Ho site, Ho(2) is bonded in a 14-coordinate geometry to two equivalent Ni(1), two equivalent Ni(3), two equivalent Ni(5), four equivalent Ni(2), and four equivalent Ni(4) atoms. There are five inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to four equivalent Ho(2), four equivalent Ni(4), and four equivalent Ni(5) atoms to form NiHo4Ni8 cuboctahedra that share corners with four equivalent C(2)Ni6 octahedra and faces with two equivalent Ni(1)Ho4Ni8 cuboctahedra. The corner-sharing octahedral tilt angles are 34°. In the second Ni site, Ni(2) is bonded in a distorted bent 150 degrees geometry to two equivalent Ho(1), two equivalent Ho(2), one C(1), and one C(2) atom. In the third Ni site, Ni(3) is bonded in a linear geometry to two equivalent Ho(1), two equivalent Ho(2), and two equivalent C(2) atoms. In the fourth Ni site, Ni(4) is bonded in a single-bond geometry to two equivalent Ho(1), two equivalent Ho(2), one Ni(1), two equivalent Ni(5), and one C(2) atom. In the fifth Ni site, Ni(5) is bonded in a 9-coordinate geometry to one Ho(1), two equivalent Ho(2), two equivalent Ni(1), and four equivalent Ni(4) atoms. There are two inequivalent C sites. In the first C site, C(1) is bonded in a 7-coordinate geometry to four equivalent Ho(1), two equivalent Ni(2), and one C(1) atom. In the second C site, C(2) is bonded to two equivalent Ni(2), two equivalent Ni(3), and two equivalent Ni(4) atoms to form CNi6 octahedra that share corners with two equivalent Ni(1)Ho4Ni8 cuboctahedra and corners with two equivalent C(2)Ni6 octahedra. The corner-sharing octahedra are not tilted.
Ho4Ni13C4 crystallizes in the orthorhombic Cmmm space group. There are two inequivalent Ho sites. In the first Ho site, Ho(1) is bonded in a 15-coordinate geometry to one Ni(5), two equivalent Ni(3), four equivalent Ni(2), four equivalent Ni(4), and four equivalent C(1) atoms. The Ho(1)-Ni(5) bond length is 2.61 Å. Both Ho(1)-Ni(3) bond lengths are 3.18 Å. All Ho(1)-Ni(2) bond lengths are 2.89 Å. All Ho(1)-Ni(4) bond lengths are 2.99 Å. All Ho(1)-C(1) bond lengths are 2.69 Å. In the second Ho site, Ho(2) is bonded in a 14-coordinate geometry to two equivalent Ni(1), two equivalent Ni(3), two equivalent Ni(5), four equivalent Ni(2), and four equivalent Ni(4) atoms. Both Ho(2)-Ni(1) bond lengths are 2.93 Å. Both Ho(2)-Ni(3) bond lengths are 3.00 Å. Both Ho(2)-Ni(5) bond lengths are 2.64 Å. All Ho(2)-Ni(2) bond lengths are 2.79 Å. All Ho(2)-Ni(4) bond lengths are 3.00 Å. There are five inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to four equivalent Ho(2), four equivalent Ni(4), and four equivalent Ni(5) atoms to form NiHo4Ni8 cuboctahedra that share corners with four equivalent C(2)Ni6 octahedra and faces with two equivalent Ni(1)Ho4Ni8 cuboctahedra. The corner-sharing octahedral tilt angles are 34°. All Ni(1)-Ni(4) bond lengths are 2.48 Å. All Ni(1)-Ni(5) bond lengths are 2.39 Å. In the second Ni site, Ni(2) is bonded in a distorted bent 150 degrees geometry to two equivalent Ho(1), two equivalent Ho(2), one C(1), and one C(2) atom. The Ni(2)-C(1) bond length is 1.89 Å. The Ni(2)-C(2) bond length is 1.87 Å. In the third Ni site, Ni(3) is bonded in a linear geometry to two equivalent Ho(1), two equivalent Ho(2), and two equivalent C(2) atoms. Both Ni(3)-C(2) bond lengths are 1.91 Å. In the fourth Ni site, Ni(4) is bonded in a single-bond geometry to two equivalent Ho(1), two equivalent Ho(2), one Ni(1), two equivalent Ni(5), and one C(2) atom. Both Ni(4)-Ni(5) bond lengths are 2.40 Å. The Ni(4)-C(2) bond length is 1.86 Å. In the fifth Ni site, Ni(5) is bonded in a 9-coordinate geometry to one Ho(1), two equivalent Ho(2), two equivalent Ni(1), and four equivalent Ni(4) atoms. There are two inequivalent C sites. In the first C site, C(1) is bonded in a 7-coordinate geometry to four equivalent Ho(1), two equivalent Ni(2), and one C(1) atom. The C(1)-C(1) bond length is 1.36 Å. In the second C site, C(2) is bonded to two equivalent Ni(2), two equivalent Ni(3), and two equivalent Ni(4) atoms to form CNi6 octahedra that share corners with two equivalent Ni(1)Ho4Ni8 cuboctahedra and corners with two equivalent C(2)Ni6 octahedra. The corner-sharing octahedra are not tilted.