Sm2Ga2(Fe5C)3 crystallizes in the trigonal R-3m space group. Sm(1) is bonded in a distorted trigonal planar geometry to three equivalent Fe(1), one Ga(1), and three equivalent C(1) atoms. There are three inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to two equivalent Sm(1), four equivalent Fe(2), four equivalent Fe(3), and two equivalent Ga(1) atoms to form distorted FeSm2Ga2Fe8 cuboctahedra that share corners with four equivalent Fe(1)Sm2Ga2Fe8 cuboctahedra, corners with two equivalent C(1)Sm2Fe4 octahedra, faces with four equivalent Fe(1)Sm2Ga2Fe8 cuboctahedra, and faces with four equivalent C(1)Sm2Fe4 octahedra. The corner-sharing octahedral tilt angles are 47°. In the second Fe site, Fe(2) is bonded in a single-bond geometry to two equivalent Fe(1), two equivalent Ga(1), and one C(1) atom. In the third Fe site, Fe(3) is bonded in a single-bond geometry to two equivalent Fe(1), one Ga(1), and one C(1) atom. Ga(1) is bonded in a 14-coordinate geometry to one Sm(1), three equivalent Fe(1), three equivalent Fe(3), six equivalent Fe(2), and one Ga(1) atom. C(1) is bonded to two equivalent Sm(1), two equivalent Fe(2), and two equivalent Fe(3) atoms to form CSm2Fe4 octahedra that share corners with two equivalent Fe(1)Sm2Ga2Fe8 cuboctahedra, corners with four equivalent C(1)Sm2Fe4 octahedra, and faces with four equivalent Fe(1)Sm2Ga2Fe8 cuboctahedra. The corner-sharing octahedral tilt angles are 61°.
Sm2Ga2(Fe5C)3 crystallizes in the trigonal R-3m space group. Sm(1) is bonded in a distorted trigonal planar geometry to three equivalent Fe(1), one Ga(1), and three equivalent C(1) atoms. All Sm(1)-Fe(1) bond lengths are 3.41 Å. The Sm(1)-Ga(1) bond length is 3.10 Å. All Sm(1)-C(1) bond lengths are 2.53 Å. There are three inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to two equivalent Sm(1), four equivalent Fe(2), four equivalent Fe(3), and two equivalent Ga(1) atoms to form distorted FeSm2Ga2Fe8 cuboctahedra that share corners with four equivalent Fe(1)Sm2Ga2Fe8 cuboctahedra, corners with two equivalent C(1)Sm2Fe4 octahedra, faces with four equivalent Fe(1)Sm2Ga2Fe8 cuboctahedra, and faces with four equivalent C(1)Sm2Fe4 octahedra. The corner-sharing octahedral tilt angles are 47°. All Fe(1)-Fe(2) bond lengths are 2.47 Å. All Fe(1)-Fe(3) bond lengths are 2.51 Å. Both Fe(1)-Ga(1) bond lengths are 2.65 Å. In the second Fe site, Fe(2) is bonded in a single-bond geometry to two equivalent Fe(1), two equivalent Ga(1), and one C(1) atom. Both Fe(2)-Ga(1) bond lengths are 2.81 Å. The Fe(2)-C(1) bond length is 1.88 Å. In the third Fe site, Fe(3) is bonded in a single-bond geometry to two equivalent Fe(1), one Ga(1), and one C(1) atom. The Fe(3)-Ga(1) bond length is 2.66 Å. The Fe(3)-C(1) bond length is 1.93 Å. Ga(1) is bonded in a 14-coordinate geometry to one Sm(1), three equivalent Fe(1), three equivalent Fe(3), six equivalent Fe(2), and one Ga(1) atom. The Ga(1)-Ga(1) bond length is 2.58 Å. C(1) is bonded to two equivalent Sm(1), two equivalent Fe(2), and two equivalent Fe(3) atoms to form CSm2Fe4 octahedra that share corners with two equivalent Fe(1)Sm2Ga2Fe8 cuboctahedra, corners with four equivalent C(1)Sm2Fe4 octahedra, and faces with four equivalent Fe(1)Sm2Ga2Fe8 cuboctahedra. The corner-sharing octahedral tilt angles are 61°.