Sm2Mn2Fe13Ga2C crystallizes in the monoclinic C2/m space group. Sm(1) is bonded in a distorted single-bond geometry to one Fe(5), four equivalent Fe(4), six equivalent Fe(2), one Ga(1), and one C(1) atom. Mn(1) is bonded in a distorted q6 geometry to two equivalent Fe(1), two equivalent Fe(2), two equivalent Fe(3), two equivalent Fe(4), and two equivalent Ga(1) atoms. There are five inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a distorted single-bond geometry to two equivalent Mn(1), two equivalent Fe(2), two equivalent Fe(4), one Ga(1), and one C(1) atom. In the second Fe site, Fe(2) is bonded to three equivalent Sm(1), one Mn(1), one Fe(1), one Fe(2), one Fe(3), one Fe(5), three equivalent Fe(4), and one Ga(1) atom to form distorted FeSm3MnGaFe7 cuboctahedra that share  a cornercorner with one Fe(5)Sm2Ga2Fe8 cuboctahedra, corners with seven equivalent Fe(2)Sm3MnGaFe7 cuboctahedra, corners with two equivalent C(1)Sm2Fe4 octahedra,  an edgeedge with one Fe(5)Sm2Ga2Fe8 cuboctahedra, edges with three equivalent Fe(2)Sm3MnGaFe7 cuboctahedra,  a faceface with one Fe(5)Sm2Ga2Fe8 cuboctahedra, faces with four equivalent Fe(2)Sm3MnGaFe7 cuboctahedra, and  a faceface with one C(1)Sm2Fe4 octahedra. The corner-sharing octahedral tilt angles range from 65-71°. In the third Fe site, Fe(3) is bonded in a distorted single-bond geometry to two equivalent Mn(1), two equivalent Fe(2), two equivalent Fe(4), two equivalent Ga(1), and one C(1) atom. In the fourth Fe site, Fe(4) is bonded in a 12-coordinate geometry to two equivalent Sm(1), one Mn(1), one Fe(1), one Fe(3), one Fe(4), one Fe(5), three equivalent Fe(2), and two equivalent Ga(1) atoms. In the fifth Fe site, Fe(5) is bonded to two equivalent Sm(1), four equivalent Fe(2), four equivalent Fe(4), and two equivalent Ga(1) atoms to form FeSm2Ga2Fe8 cuboctahedra that share corners with four equivalent Fe(2)Sm3MnGaFe7 cuboctahedra, corners with two equivalent C(1)Sm2Fe4 octahedra, edges with four equivalent Fe(2)Sm3MnGaFe7 cuboctahedra, and faces with four equivalent Fe(2)Sm3MnGaFe7 cuboctahedra. The corner-sharing octahedral tilt angles are 47°. Ga(1) is bonded in a 14-coordinate geometry to one Sm(1), two equivalent Mn(1), one Fe(1), one Fe(5), two equivalent Fe(2), two equivalent Fe(3), four equivalent Fe(4), and one Ga(1) atom. C(1) is bonded to two equivalent Sm(1), two equivalent Fe(1), and two equivalent Fe(3) atoms to form CSm2Fe4 octahedra that share corners with two equivalent Fe(5)Sm2Ga2Fe8 cuboctahedra, corners with eight equivalent Fe(2)Sm3MnGaFe7 cuboctahedra, and faces with four equivalent Fe(2)Sm3MnGaFe7 cuboctahedra.
Sm2Mn2Fe13Ga2C crystallizes in the monoclinic C2/m space group. Sm(1) is bonded in a distorted single-bond geometry to one Fe(5), four equivalent Fe(4), six equivalent Fe(2), one Ga(1), and one C(1) atom. The Sm(1)-Fe(5) bond length is 3.31 Å. There are two shorter (3.01 Å) and two longer (3.06 Å) Sm(1)-Fe(4) bond lengths. There are a spread of Sm(1)-Fe(2) bond distances ranging from 3.05-3.24 Å. The Sm(1)-Ga(1) bond length is 3.05 Å. The Sm(1)-C(1) bond length is 2.55 Å. Mn(1) is bonded in a distorted q6 geometry to two equivalent Fe(1), two equivalent Fe(2), two equivalent Fe(3), two equivalent Fe(4), and two equivalent Ga(1) atoms. Both Mn(1)-Fe(1) bond lengths are 2.47 Å. Both Mn(1)-Fe(2) bond lengths are 2.48 Å. Both Mn(1)-Fe(3) bond lengths are 2.44 Å. Both Mn(1)-Fe(4) bond lengths are 2.44 Å. Both Mn(1)-Ga(1) bond lengths are 2.60 Å. There are five inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a distorted single-bond geometry to two equivalent Mn(1), two equivalent Fe(2), two equivalent Fe(4), one Ga(1), and one C(1) atom. Both Fe(1)-Fe(2) bond lengths are 2.52 Å. Both Fe(1)-Fe(4) bond lengths are 2.58 Å. The Fe(1)-Ga(1) bond length is 2.62 Å. The Fe(1)-C(1) bond length is 1.92 Å. In the second Fe site, Fe(2) is bonded to three equivalent Sm(1), one Mn(1), one Fe(1), one Fe(2), one Fe(3), one Fe(5), three equivalent Fe(4), and one Ga(1) atom to form distorted FeSm3MnGaFe7 cuboctahedra that share  a cornercorner with one Fe(5)Sm2Ga2Fe8 cuboctahedra, corners with seven equivalent Fe(2)Sm3MnGaFe7 cuboctahedra, corners with two equivalent C(1)Sm2Fe4 octahedra,  an edgeedge with one Fe(5)Sm2Ga2Fe8 cuboctahedra, edges with three equivalent Fe(2)Sm3MnGaFe7 cuboctahedra,  a faceface with one Fe(5)Sm2Ga2Fe8 cuboctahedra, faces with four equivalent Fe(2)Sm3MnGaFe7 cuboctahedra, and  a faceface with one C(1)Sm2Fe4 octahedra. The corner-sharing octahedral tilt angles range from 65-71°. The Fe(2)-Fe(2) bond length is 2.49 Å. The Fe(2)-Fe(3) bond length is 2.55 Å. The Fe(2)-Fe(5) bond length is 2.46 Å. There is one shorter (2.55 Å) and two longer (2.66 Å) Fe(2)-Fe(4) bond lengths. The Fe(2)-Ga(1) bond length is 2.63 Å. In the third Fe site, Fe(3) is bonded in a distorted single-bond geometry to two equivalent Mn(1), two equivalent Fe(2), two equivalent Fe(4), two equivalent Ga(1), and one C(1) atom. Both Fe(3)-Fe(4) bond lengths are 2.48 Å. Both Fe(3)-Ga(1) bond lengths are 2.77 Å. The Fe(3)-C(1) bond length is 1.83 Å. In the fourth Fe site, Fe(4) is bonded in a 12-coordinate geometry to two equivalent Sm(1), one Mn(1), one Fe(1), one Fe(3), one Fe(4), one Fe(5), three equivalent Fe(2), and two equivalent Ga(1) atoms. The Fe(4)-Fe(4) bond length is 2.51 Å. The Fe(4)-Fe(5) bond length is 2.46 Å. There is one shorter (2.81 Å) and one longer (2.82 Å) Fe(4)-Ga(1) bond length. In the fifth Fe site, Fe(5) is bonded to two equivalent Sm(1), four equivalent Fe(2), four equivalent Fe(4), and two equivalent Ga(1) atoms to form FeSm2Ga2Fe8 cuboctahedra that share corners with four equivalent Fe(2)Sm3MnGaFe7 cuboctahedra, corners with two equivalent C(1)Sm2Fe4 octahedra, edges with four equivalent Fe(2)Sm3MnGaFe7 cuboctahedra, and faces with four equivalent Fe(2)Sm3MnGaFe7 cuboctahedra. The corner-sharing octahedral tilt angles are 47°. Both Fe(5)-Ga(1) bond lengths are 2.61 Å. Ga(1) is bonded in a 14-coordinate geometry to one Sm(1), two equivalent Mn(1), one Fe(1), one Fe(5), two equivalent Fe(2), two equivalent Fe(3), four equivalent Fe(4), 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(1), and two equivalent Fe(3) atoms to form CSm2Fe4 octahedra that share corners with two equivalent Fe(5)Sm2Ga2Fe8 cuboctahedra, corners with eight equivalent Fe(2)Sm3MnGaFe7 cuboctahedra, and faces with four equivalent Fe(2)Sm3MnGaFe7 cuboctahedra.