Ho2Mn17C3 crystallizes in the hexagonal P6_3/mmc space group. There are three inequivalent Ho sites. In the first Ho site, Ho(1) is bonded in a distorted trigonal planar geometry to two equivalent Mn(2), six equivalent Mn(4), and three equivalent C(1) atoms. In the second Ho site, Ho(1) is bonded in a distorted trigonal planar geometry to two equivalent Mn(2), six equivalent Mn(4), and three equivalent C(1) atoms. In the third Ho site, Ho(2) is bonded in a trigonal planar geometry to three equivalent C(1) atoms. There are four inequivalent Mn sites. In the first Mn site, Mn(4) is bonded to two Ho(1,1); two equivalent Mn(2); four equivalent Mn(1); and four equivalent Mn(3) atoms to form MnHo2Mn10 cuboctahedra that share corners with four equivalent Mn(4)Ho2Mn10 cuboctahedra, corners with two equivalent C(1)Ho2Mn4 octahedra, faces with six equivalent Mn(4)Ho2Mn10 cuboctahedra, and faces with four equivalent C(1)Ho2Mn4 octahedra. The corner-sharing octahedral tilt angles are 40°. In the second Mn site, Mn(1) is bonded in a single-bond geometry to two equivalent Mn(2), two equivalent Mn(4), and one C(1) atom. In the third Mn site, Mn(2) is bonded in a 14-coordinate geometry to one Ho(1), one Mn(2), three equivalent Mn(3), three equivalent Mn(4), and six equivalent Mn(1) atoms. In the fourth Mn site, Mn(3) is bonded in a single-bond geometry to one Mn(2), two equivalent Mn(4), and one C(1) atom. C(1) is bonded to one Ho(1), one Ho(2), two equivalent Mn(1), and two equivalent Mn(3) atoms to form CHo2Mn4 octahedra that share corners with two equivalent Mn(4)Ho2Mn10 cuboctahedra, corners with four equivalent C(1)Ho2Mn4 octahedra, and faces with four equivalent Mn(4)Ho2Mn10 cuboctahedra. The corner-sharing octahedral tilt angles are 60°.
Ho2Mn17C3 crystallizes in the hexagonal P6_3/mmc space group. There are three inequivalent Ho sites. In the first Ho site, Ho(1) is bonded in a distorted trigonal planar geometry to two equivalent Mn(2), six equivalent Mn(4), and three equivalent C(1) atoms. Both Ho(1)-Mn(2) bond lengths are 2.95 Å. All Ho(1)-Mn(4) bond lengths are 3.21 Å. All Ho(1)-C(1) bond lengths are 2.48 Å. In the second Ho site, Ho(1) is bonded in a distorted trigonal planar geometry to two equivalent Mn(2), six equivalent Mn(4), and three equivalent C(1) atoms. Both Ho(1)-Mn(2) bond lengths are 2.95 Å. All Ho(1)-Mn(4) bond lengths are 3.21 Å. All Ho(1)-C(1) bond lengths are 2.48 Å. In the third Ho site, Ho(2) is bonded in a trigonal planar geometry to three equivalent C(1) atoms. All Ho(2)-C(1) bond lengths are 2.43 Å. There are four inequivalent Mn sites. In the first Mn site, Mn(4) is bonded to two Ho(1,1); two equivalent Mn(2); four equivalent Mn(1); and four equivalent Mn(3) atoms to form MnHo2Mn10 cuboctahedra that share corners with four equivalent Mn(4)Ho2Mn10 cuboctahedra, corners with two equivalent C(1)Ho2Mn4 octahedra, faces with six equivalent Mn(4)Ho2Mn10 cuboctahedra, and faces with four equivalent C(1)Ho2Mn4 octahedra. The corner-sharing octahedral tilt angles are 40°. Both Mn(4)-Mn(2) bond lengths are 2.61 Å. All Mn(4)-Mn(1) bond lengths are 2.44 Å. All Mn(4)-Mn(3) bond lengths are 2.45 Å. In the second Mn site, Mn(1) is bonded in a single-bond geometry to two equivalent Mn(2), two equivalent Mn(4), and one C(1) atom. Both Mn(1)-Mn(2) bond lengths are 2.63 Å. The Mn(1)-C(1) bond length is 1.91 Å. In the third Mn site, Mn(2) is bonded in a 14-coordinate geometry to one Ho(1), one Mn(2), three equivalent Mn(3), three equivalent Mn(4), and six equivalent Mn(1) atoms. The Mn(2)-Mn(2) bond length is 2.38 Å. All Mn(2)-Mn(3) bond lengths are 2.65 Å. In the fourth Mn site, Mn(3) is bonded in a single-bond geometry to one Mn(2), two equivalent Mn(4), and one C(1) atom. The Mn(3)-C(1) bond length is 1.86 Å. C(1) is bonded to one Ho(1), one Ho(2), two equivalent Mn(1), and two equivalent Mn(3) atoms to form CHo2Mn4 octahedra that share corners with two equivalent Mn(4)Ho2Mn10 cuboctahedra, corners with four equivalent C(1)Ho2Mn4 octahedra, and faces with four equivalent Mn(4)Ho2Mn10 cuboctahedra. The corner-sharing octahedral tilt angles are 60°.