Tm2Mn17C3 crystallizes in the hexagonal P6_3/mmc space group. There are three inequivalent Tm sites. In the first Tm site, Tm(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 Tm site, Tm(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 Tm site, Tm(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 Tm(1,1); two equivalent Mn(2); four equivalent Mn(1); and four equivalent Mn(3) atoms to form distorted MnTm2Mn10 cuboctahedra that share corners with four equivalent Mn(4)Tm2Mn10 cuboctahedra, corners with two equivalent C(1)Tm2Mn4 octahedra, faces with six equivalent Mn(4)Tm2Mn10 cuboctahedra, and faces with four equivalent C(1)Tm2Mn4 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 Tm(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 Tm(1), one Tm(2), two equivalent Mn(1), and two equivalent Mn(3) atoms to form CTm2Mn4 octahedra that share corners with two equivalent Mn(4)Tm2Mn10 cuboctahedra, corners with four equivalent C(1)Tm2Mn4 octahedra, and faces with four equivalent Mn(4)Tm2Mn10 cuboctahedra. The corner-sharing octahedral tilt angles are 60°.
Tm2Mn17C3 crystallizes in the hexagonal P6_3/mmc space group. There are three inequivalent Tm sites. In the first Tm site, Tm(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 Tm(1)-Mn(2) bond lengths are 2.94 Å. All Tm(1)-Mn(4) bond lengths are 3.20 Å. All Tm(1)-C(1) bond lengths are 2.48 Å. In the second Tm site, Tm(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 Tm(1)-Mn(2) bond lengths are 2.94 Å. All Tm(1)-Mn(4) bond lengths are 3.20 Å. All Tm(1)-C(1) bond lengths are 2.48 Å. In the third Tm site, Tm(2) is bonded in a trigonal planar geometry to three equivalent C(1) atoms. All Tm(2)-C(1) bond lengths are 2.41 Å. There are four inequivalent Mn sites. In the first Mn site, Mn(4) is bonded to two Tm(1,1); two equivalent Mn(2); four equivalent Mn(1); and four equivalent Mn(3) atoms to form distorted MnTm2Mn10 cuboctahedra that share corners with four equivalent Mn(4)Tm2Mn10 cuboctahedra, corners with two equivalent C(1)Tm2Mn4 octahedra, faces with six equivalent Mn(4)Tm2Mn10 cuboctahedra, and faces with four equivalent C(1)Tm2Mn4 octahedra. The corner-sharing octahedral tilt angles are 40°. Both Mn(4)-Mn(2) bond lengths are 2.60 Å. All Mn(4)-Mn(1) bond lengths are 2.42 Å. All Mn(4)-Mn(3) bond lengths are 2.43 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 2.62 Å. The Mn(1)-C(1) bond length is 1.90 Å. In the third Mn site, Mn(2) is bonded in a 14-coordinate geometry to one Tm(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 2.37 Å. All Mn(2)-Mn(3) bond lengths are 2.62 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 Tm(1), one Tm(2), two equivalent Mn(1), and two equivalent Mn(3) atoms to form CTm2Mn4 octahedra that share corners with two equivalent Mn(4)Tm2Mn10 cuboctahedra, corners with four equivalent C(1)Tm2Mn4 octahedra, and faces with four equivalent Mn(4)Tm2Mn10 cuboctahedra. The corner-sharing octahedral tilt angles are 60°.