The structure described by Sm2Fe15Ga2C2 crystallizes in the monoclinic Cm space group. There are two inequivalent Sm sites. In the first Sm site, Sm(1) is bonded in a distorted bent 120 degrees geometry to one Fe(1), one Fe(7), one Fe(8), two equivalent Fe(10), two equivalent Fe(5), two equivalent Fe(6), and two equivalent C(1) atoms. In the second Sm site, Sm(2) is bonded in a distorted bent 120 degrees geometry to one Fe(10), one Fe(2), one Fe(7), two equivalent Fe(5), two equivalent Fe(6), two equivalent Fe(8), and two equivalent C(1) atoms. There are ten inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a 14-coordinate geometry to one Sm(1), one Fe(10), one Fe(2), one Fe(7), two equivalent Fe(3), two equivalent Fe(4), two equivalent Fe(5), two equivalent Fe(6), and two equivalent Ga(1) atoms. In the second Fe site, Fe(2) is bonded in a 14-coordinate geometry to one Sm(2), one Fe(1), one Fe(7), one Fe(8), two equivalent Fe(3), two equivalent Fe(4), two equivalent Fe(5), two equivalent Fe(6), and two equivalent Fe(9) atoms. In the third Fe site, Fe(3) is bonded in a single-bond geometry to one Fe(1), one Fe(10), one Fe(2), one Fe(5), one Fe(6), one Fe(7), and one C(1) atom. In the fourth Fe site, Fe(4) is bonded in a single-bond geometry to one Fe(1), one Fe(2), one Fe(5), one Fe(6), one Fe(7), one Fe(8), and one C(1) atom. In the fifth Fe site, Fe(5) is bonded to one Sm(1), one Sm(2), one Fe(1), one Fe(10), one Fe(2), one Fe(3), one Fe(4), one Fe(8), one Fe(9), two equivalent Fe(6), and one Ga(1) atom to form distorted FeSm2GaFe9 cuboctahedra that share  a cornercorner with one Fe(10)Sm3Fe9 cuboctahedra,  a cornercorner with one Fe(8)Sm3Ga2Fe7 cuboctahedra, corners with two equivalent Fe(7)Sm2Ga2Fe8 cuboctahedra, corners with two equivalent Fe(5)Sm2GaFe9 cuboctahedra, corners with two equivalent Fe(6)Sm2GaFe9 cuboctahedra, corners with four equivalent C(1)Sm2GaFe3 octahedra,  an edgeedge with one Fe(5)Sm2GaFe9 cuboctahedra, edges with two equivalent Fe(6)Sm2GaFe9 cuboctahedra, edges with two equivalent C(1)Sm2GaFe3 octahedra,  a faceface with one Fe(5)Sm2GaFe9 cuboctahedra, faces with two equivalent Fe(7)Sm2Ga2Fe8 cuboctahedra, faces with two equivalent Fe(6)Sm2GaFe9 cuboctahedra, faces with two equivalent Fe(10)Sm3Fe9 cuboctahedra, and faces with two equivalent Fe(8)Sm3Ga2Fe7 cuboctahedra. The corner-sharing octahedral tilt angles range from 22-30°. In the sixth Fe site, Fe(6) is bonded to one Sm(1), one Sm(2), one Fe(1), one Fe(10), one Fe(2), one Fe(3), one Fe(4), one Fe(8), one Fe(9), two equivalent Fe(5), and one Ga(1) atom to form distorted FeSm2GaFe9 cuboctahedra that share  a cornercorner with one Fe(10)Sm3Fe9 cuboctahedra,  a cornercorner with one Fe(8)Sm3Ga2Fe7 cuboctahedra, corners with two equivalent Fe(7)Sm2Ga2Fe8 cuboctahedra, corners with two equivalent Fe(5)Sm2GaFe9 cuboctahedra, corners with two equivalent Fe(6)Sm2GaFe9 cuboctahedra, corners with two equivalent C(1)Sm2GaFe3 octahedra,  an edgeedge with one Fe(10)Sm3Fe9 cuboctahedra,  an edgeedge with one Fe(8)Sm3Ga2Fe7 cuboctahedra, edges with two equivalent Fe(5)Sm2GaFe9 cuboctahedra,  a faceface with one Fe(10)Sm3Fe9 cuboctahedra,  a faceface with one Fe(8)Sm3Ga2Fe7 cuboctahedra, faces with two equivalent Fe(7)Sm2Ga2Fe8 cuboctahedra, faces with two equivalent Fe(5)Sm2GaFe9 cuboctahedra, faces with two equivalent Fe(6)Sm2GaFe9 cuboctahedra, and faces with two equivalent C(1)Sm2GaFe3 octahedra. The corner-sharing octahedral tilt angles range from 40-47°. In the seventh Fe site, Fe(7) is bonded to one Sm(1), one Sm(2), one Fe(1), one Fe(2), two equivalent Fe(3), two equivalent Fe(4), two equivalent Fe(9), and two equivalent Ga(1) atoms to form distorted FeSm2Ga2Fe8 cuboctahedra that share corners with three equivalent Fe(10)Sm3Fe9 cuboctahedra, corners with three equivalent Fe(8)Sm3Ga2Fe7 cuboctahedra, corners with four equivalent Fe(5)Sm2GaFe9 cuboctahedra, corners with four equivalent Fe(6)Sm2GaFe9 cuboctahedra,  an edgeedge with one Fe(10)Sm3Fe9 cuboctahedra,  an edgeedge with one Fe(8)Sm3Ga2Fe7 cuboctahedra,  a faceface with one Fe(10)Sm3Fe9 cuboctahedra,  a faceface with one Fe(8)Sm3Ga2Fe7 cuboctahedra, faces with four equivalent Fe(5)Sm2GaFe9 cuboctahedra, faces with four equivalent Fe(6)Sm2GaFe9 cuboctahedra, and faces with four equivalent C(1)Sm2GaFe3 octahedra. In the eighth Fe site, Fe(8) is bonded to one Sm(1), two equivalent Sm(2), one Fe(2), two equivalent Fe(4), two equivalent Fe(5), two equivalent Fe(6), and two equivalent Ga(1) atoms to form distorted FeSm3Ga2Fe7 cuboctahedra that share corners with two equivalent Fe(5)Sm2GaFe9 cuboctahedra, corners with two equivalent Fe(6)Sm2GaFe9 cuboctahedra, corners with two equivalent Fe(10)Sm3Fe9 cuboctahedra, corners with two equivalent Fe(8)Sm3Ga2Fe7 cuboctahedra, corners with three equivalent Fe(7)Sm2Ga2Fe8 cuboctahedra, corners with four equivalent C(1)Sm2GaFe3 octahedra,  an edgeedge with one Fe(7)Sm2Ga2Fe8 cuboctahedra,  an edgeedge with one Fe(10)Sm3Fe9 cuboctahedra, edges with two equivalent Fe(6)Sm2GaFe9 cuboctahedra,  a faceface with one Fe(7)Sm2Ga2Fe8 cuboctahedra,  a faceface with one Fe(10)Sm3Fe9 cuboctahedra, faces with two equivalent Fe(6)Sm2GaFe9 cuboctahedra, faces with four equivalent Fe(5)Sm2GaFe9 cuboctahedra, and faces with two equivalent C(1)Sm2GaFe3 octahedra. The corner-sharing octahedral tilt angles range from 66-70°. In the ninth Fe site, Fe(9) is bonded in a single-bond geometry to one Fe(10), one Fe(2), one Fe(5), one Fe(6), one Fe(7), and one C(1) atom. In the tenth Fe site, Fe(10) is bonded to one Sm(2), two equivalent Sm(1), one Fe(1), two equivalent Fe(3), two equivalent Fe(5), two equivalent Fe(6), and two equivalent Fe(9) atoms to form distorted FeSm3Fe9 cuboctahedra that share corners with two equivalent Fe(5)Sm2GaFe9 cuboctahedra, corners with two equivalent Fe(6)Sm2GaFe9 cuboctahedra, corners with two equivalent Fe(10)Sm3Fe9 cuboctahedra, corners with two equivalent Fe(8)Sm3Ga2Fe7 cuboctahedra, corners with three equivalent Fe(7)Sm2Ga2Fe8 cuboctahedra, corners with four equivalent C(1)Sm2GaFe3 octahedra,  an edgeedge with one Fe(7)Sm2Ga2Fe8 cuboctahedra,  an edgeedge with one Fe(8)Sm3Ga2Fe7 cuboctahedra, edges with two equivalent Fe(6)Sm2GaFe9 cuboctahedra,  a faceface with one Fe(7)Sm2Ga2Fe8 cuboctahedra,  a faceface with one Fe(8)Sm3Ga2Fe7 cuboctahedra, faces with two equivalent Fe(6)Sm2GaFe9 cuboctahedra, faces with four equivalent Fe(5)Sm2GaFe9 cuboctahedra, and faces with two equivalent C(1)Sm2GaFe3 octahedra. The corner-sharing octahedral tilt angles range from 62-66°. Ga(1) is bonded in a single-bond geometry to one Fe(1), one Fe(5), one Fe(6), one Fe(7), one Fe(8), and one C(1) atom. C(1) is bonded to one Sm(1), one Sm(2), one Fe(3), one Fe(4), one Fe(9), and one Ga(1) atom to form CSm2GaFe3 octahedra that share corners with two equivalent Fe(6)Sm2GaFe9 cuboctahedra, corners with two equivalent Fe(10)Sm3Fe9 cuboctahedra, corners with two equivalent Fe(8)Sm3Ga2Fe7 cuboctahedra, corners with four equivalent Fe(5)Sm2GaFe9 cuboctahedra, corners with two equivalent C(1)Sm2GaFe3 octahedra, edges with two equivalent Fe(5)Sm2GaFe9 cuboctahedra,  a faceface with one Fe(10)Sm3Fe9 cuboctahedra,  a faceface with one Fe(8)Sm3Ga2Fe7 cuboctahedra, faces with two equivalent Fe(7)Sm2Ga2Fe8 cuboctahedra, and faces with two equivalent Fe(6)Sm2GaFe9 cuboctahedra. The corner-sharing octahedral tilt angles range from 62-64°. is represented by the CIF card [CIF]
data_Sm2Ga2Fe15C2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.516
_cell_length_b   6.516
_cell_length_c   6.579
_cell_angle_alpha   82.834
_cell_angle_beta   82.834
_cell_angle_gamma   83.001
_symmetry_Int_Tables_number   1
_cell_volume   273.340
_cell_formula_units_Z   1
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
loop_
 _atom_site_type_symbol
 _atom_site_label
 _atom_site_symmetry_multiplicity
 _atom_site_fract_x
 _atom_site_fract_y
 _atom_site_fract_z
 _atom_site_occupancy
  Sm  Sm0  1  0.343  0.343  0.331  1.0
  Sm  Sm1  1  0.655  0.655  0.668  1.0
  Ga  Ga2  1  0.337  0.843  0.337  1.0
  Ga  Ga3  1  0.843  0.337  0.337  1.0
  Fe  Fe4  1  0.095  0.095  0.089  1.0
  Fe  Fe5  1  0.903  0.903  0.906  1.0
  Fe  Fe6  1  0.286  0.001  0.711  1.0
  Fe  Fe7  1  0.992  0.712  0.287  1.0
  Fe  Fe8  1  0.718  0.283  0.996  1.0
  Fe  Fe9  1  0.001  0.286  0.711  1.0
  Fe  Fe10  1  0.283  0.718  0.996  1.0
  Fe  Fe11  1  0.712  0.992  0.287  1.0
  Fe  Fe12  1  0.002  0.500  0.998  1.0
  Fe  Fe13  1  0.500  0.002  0.998  1.0
  Fe  Fe14  1  0.997  0.997  0.508  1.0
  Fe  Fe15  1  0.663  0.663  0.136  1.0
  Fe  Fe16  1  0.657  0.148  0.665  1.0
  Fe  Fe17  1  0.148  0.657  0.665  1.0
  Fe  Fe18  1  0.343  0.343  0.854  1.0
  C  C19  1  0.510  0.011  0.509  1.0
  C  C20  1  0.011  0.510  0.509  1.0
[/CIF]
.
The structure described by Sm2Fe15Ga2C2 crystallizes in the monoclinic Cm space group. There are two inequivalent Sm sites. In the first Sm site, Sm(1) is bonded in a distorted bent 120 degrees geometry to one Fe(1), one Fe(7), one Fe(8), two equivalent Fe(10), two equivalent Fe(5), two equivalent Fe(6), and two equivalent C(1) atoms. In the second Sm site, Sm(2) is bonded in a distorted bent 120 degrees geometry to one Fe(10), one Fe(2), one Fe(7), two equivalent Fe(5), two equivalent Fe(6), two equivalent Fe(8), and two equivalent C(1) atoms. There are ten inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a 14-coordinate geometry to one Sm(1), one Fe(10), one Fe(2), one Fe(7), two equivalent Fe(3), two equivalent Fe(4), two equivalent Fe(5), two equivalent Fe(6), and two equivalent Ga(1) atoms. In the second Fe site, Fe(2) is bonded in a 14-coordinate geometry to one Sm(2), one Fe(1), one Fe(7), one Fe(8), two equivalent Fe(3), two equivalent Fe(4), two equivalent Fe(5), two equivalent Fe(6), and two equivalent Fe(9) atoms. In the third Fe site, Fe(3) is bonded in a single-bond geometry to one Fe(1), one Fe(10), one Fe(2), one Fe(5), one Fe(6), one Fe(7), and one C(1) atom. In the fourth Fe site, Fe(4) is bonded in a single-bond geometry to one Fe(1), one Fe(2), one Fe(5), one Fe(6), one Fe(7), one Fe(8), and one C(1) atom. In the fifth Fe site, Fe(5) is bonded to one Sm(1), one Sm(2), one Fe(1), one Fe(10), one Fe(2), one Fe(3), one Fe(4), one Fe(8), one Fe(9), two equivalent Fe(6), and one Ga(1) atom to form distorted FeSm2GaFe9 cuboctahedra that share  a cornercorner with one Fe(10)Sm3Fe9 cuboctahedra,  a cornercorner with one Fe(8)Sm3Ga2Fe7 cuboctahedra, corners with two equivalent Fe(7)Sm2Ga2Fe8 cuboctahedra, corners with two equivalent Fe(5)Sm2GaFe9 cuboctahedra, corners with two equivalent Fe(6)Sm2GaFe9 cuboctahedra, corners with four equivalent C(1)Sm2GaFe3 octahedra,  an edgeedge with one Fe(5)Sm2GaFe9 cuboctahedra, edges with two equivalent Fe(6)Sm2GaFe9 cuboctahedra, edges with two equivalent C(1)Sm2GaFe3 octahedra,  a faceface with one Fe(5)Sm2GaFe9 cuboctahedra, faces with two equivalent Fe(7)Sm2Ga2Fe8 cuboctahedra, faces with two equivalent Fe(6)Sm2GaFe9 cuboctahedra, faces with two equivalent Fe(10)Sm3Fe9 cuboctahedra, and faces with two equivalent Fe(8)Sm3Ga2Fe7 cuboctahedra. The corner-sharing octahedral tilt angles range from 22-30°. In the sixth Fe site, Fe(6) is bonded to one Sm(1), one Sm(2), one Fe(1), one Fe(10), one Fe(2), one Fe(3), one Fe(4), one Fe(8), one Fe(9), two equivalent Fe(5), and one Ga(1) atom to form distorted FeSm2GaFe9 cuboctahedra that share  a cornercorner with one Fe(10)Sm3Fe9 cuboctahedra,  a cornercorner with one Fe(8)Sm3Ga2Fe7 cuboctahedra, corners with two equivalent Fe(7)Sm2Ga2Fe8 cuboctahedra, corners with two equivalent Fe(5)Sm2GaFe9 cuboctahedra, corners with two equivalent Fe(6)Sm2GaFe9 cuboctahedra, corners with two equivalent C(1)Sm2GaFe3 octahedra,  an edgeedge with one Fe(10)Sm3Fe9 cuboctahedra,  an edgeedge with one Fe(8)Sm3Ga2Fe7 cuboctahedra, edges with two equivalent Fe(5)Sm2GaFe9 cuboctahedra,  a faceface with one Fe(10)Sm3Fe9 cuboctahedra,  a faceface with one Fe(8)Sm3Ga2Fe7 cuboctahedra, faces with two equivalent Fe(7)Sm2Ga2Fe8 cuboctahedra, faces with two equivalent Fe(5)Sm2GaFe9 cuboctahedra, faces with two equivalent Fe(6)Sm2GaFe9 cuboctahedra, and faces with two equivalent C(1)Sm2GaFe3 octahedra. The corner-sharing octahedral tilt angles range from 40-47°. In the seventh Fe site, Fe(7) is bonded to one Sm(1), one Sm(2), one Fe(1), one Fe(2), two equivalent Fe(3), two equivalent Fe(4), two equivalent Fe(9), and two equivalent Ga(1) atoms to form distorted FeSm2Ga2Fe8 cuboctahedra that share corners with three equivalent Fe(10)Sm3Fe9 cuboctahedra, corners with three equivalent Fe(8)Sm3Ga2Fe7 cuboctahedra, corners with four equivalent Fe(5)Sm2GaFe9 cuboctahedra, corners with four equivalent Fe(6)Sm2GaFe9 cuboctahedra,  an edgeedge with one Fe(10)Sm3Fe9 cuboctahedra,  an edgeedge with one Fe(8)Sm3Ga2Fe7 cuboctahedra,  a faceface with one Fe(10)Sm3Fe9 cuboctahedra,  a faceface with one Fe(8)Sm3Ga2Fe7 cuboctahedra, faces with four equivalent Fe(5)Sm2GaFe9 cuboctahedra, faces with four equivalent Fe(6)Sm2GaFe9 cuboctahedra, and faces with four equivalent C(1)Sm2GaFe3 octahedra. In the eighth Fe site, Fe(8) is bonded to one Sm(1), two equivalent Sm(2), one Fe(2), two equivalent Fe(4), two equivalent Fe(5), two equivalent Fe(6), and two equivalent Ga(1) atoms to form distorted FeSm3Ga2Fe7 cuboctahedra that share corners with two equivalent Fe(5)Sm2GaFe9 cuboctahedra, corners with two equivalent Fe(6)Sm2GaFe9 cuboctahedra, corners with two equivalent Fe(10)Sm3Fe9 cuboctahedra, corners with two equivalent Fe(8)Sm3Ga2Fe7 cuboctahedra, corners with three equivalent Fe(7)Sm2Ga2Fe8 cuboctahedra, corners with four equivalent C(1)Sm2GaFe3 octahedra,  an edgeedge with one Fe(7)Sm2Ga2Fe8 cuboctahedra,  an edgeedge with one Fe(10)Sm3Fe9 cuboctahedra, edges with two equivalent Fe(6)Sm2GaFe9 cuboctahedra,  a faceface with one Fe(7)Sm2Ga2Fe8 cuboctahedra,  a faceface with one Fe(10)Sm3Fe9 cuboctahedra, faces with two equivalent Fe(6)Sm2GaFe9 cuboctahedra, faces with four equivalent Fe(5)Sm2GaFe9 cuboctahedra, and faces with two equivalent C(1)Sm2GaFe3 octahedra. The corner-sharing octahedral tilt angles range from 66-70°. In the ninth Fe site, Fe(9) is bonded in a single-bond geometry to one Fe(10), one Fe(2), one Fe(5), one Fe(6), one Fe(7), and one C(1) atom. In the tenth Fe site, Fe(10) is bonded to one Sm(2), two equivalent Sm(1), one Fe(1), two equivalent Fe(3), two equivalent Fe(5), two equivalent Fe(6), and two equivalent Fe(9) atoms to form distorted FeSm3Fe9 cuboctahedra that share corners with two equivalent Fe(5)Sm2GaFe9 cuboctahedra, corners with two equivalent Fe(6)Sm2GaFe9 cuboctahedra, corners with two equivalent Fe(10)Sm3Fe9 cuboctahedra, corners with two equivalent Fe(8)Sm3Ga2Fe7 cuboctahedra, corners with three equivalent Fe(7)Sm2Ga2Fe8 cuboctahedra, corners with four equivalent C(1)Sm2GaFe3 octahedra,  an edgeedge with one Fe(7)Sm2Ga2Fe8 cuboctahedra,  an edgeedge with one Fe(8)Sm3Ga2Fe7 cuboctahedra, edges with two equivalent Fe(6)Sm2GaFe9 cuboctahedra,  a faceface with one Fe(7)Sm2Ga2Fe8 cuboctahedra,  a faceface with one Fe(8)Sm3Ga2Fe7 cuboctahedra, faces with two equivalent Fe(6)Sm2GaFe9 cuboctahedra, faces with four equivalent Fe(5)Sm2GaFe9 cuboctahedra, and faces with two equivalent C(1)Sm2GaFe3 octahedra. The corner-sharing octahedral tilt angles range from 62-66°. Ga(1) is bonded in a single-bond geometry to one Fe(1), one Fe(5), one Fe(6), one Fe(7), one Fe(8), and one C(1) atom. C(1) is bonded to one Sm(1), one Sm(2), one Fe(3), one Fe(4), one Fe(9), and one Ga(1) atom to form CSm2GaFe3 octahedra that share corners with two equivalent Fe(6)Sm2GaFe9 cuboctahedra, corners with two equivalent Fe(10)Sm3Fe9 cuboctahedra, corners with two equivalent Fe(8)Sm3Ga2Fe7 cuboctahedra, corners with four equivalent Fe(5)Sm2GaFe9 cuboctahedra, corners with two equivalent C(1)Sm2GaFe3 octahedra, edges with two equivalent Fe(5)Sm2GaFe9 cuboctahedra,  a faceface with one Fe(10)Sm3Fe9 cuboctahedra,  a faceface with one Fe(8)Sm3Ga2Fe7 cuboctahedra, faces with two equivalent Fe(7)Sm2Ga2Fe8 cuboctahedra, and faces with two equivalent Fe(6)Sm2GaFe9 cuboctahedra. The corner-sharing octahedral tilt angles range from 62-64°. is represented by the CIF card [CIF]
data_Sm2Ga2Fe15C2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.516
_cell_length_b   6.516
_cell_length_c   6.579
_cell_angle_alpha   82.834
_cell_angle_beta   82.834
_cell_angle_gamma   83.001
_symmetry_Int_Tables_number   1
_cell_volume   273.340
_cell_formula_units_Z   1
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
loop_
 _atom_site_type_symbol
 _atom_site_label
 _atom_site_symmetry_multiplicity
 _atom_site_fract_x
 _atom_site_fract_y
 _atom_site_fract_z
 _atom_site_occupancy
  Sm  Sm0  1  0.343  0.343  0.331  1.0
  Sm  Sm1  1  0.655  0.655  0.668  1.0
  Ga  Ga2  1  0.337  0.843  0.337  1.0
  Ga  Ga3  1  0.843  0.337  0.337  1.0
  Fe  Fe4  1  0.095  0.095  0.089  1.0
  Fe  Fe5  1  0.903  0.903  0.906  1.0
  Fe  Fe6  1  0.286  0.001  0.711  1.0
  Fe  Fe7  1  0.992  0.712  0.287  1.0
  Fe  Fe8  1  0.718  0.283  0.996  1.0
  Fe  Fe9  1  0.001  0.286  0.711  1.0
  Fe  Fe10  1  0.283  0.718  0.996  1.0
  Fe  Fe11  1  0.712  0.992  0.287  1.0
  Fe  Fe12  1  0.002  0.500  0.998  1.0
  Fe  Fe13  1  0.500  0.002  0.998  1.0
  Fe  Fe14  1  0.997  0.997  0.508  1.0
  Fe  Fe15  1  0.663  0.663  0.136  1.0
  Fe  Fe16  1  0.657  0.148  0.665  1.0
  Fe  Fe17  1  0.148  0.657  0.665  1.0
  Fe  Fe18  1  0.343  0.343  0.854  1.0
  C  C19  1  0.510  0.011  0.509  1.0
  C  C20  1  0.011  0.510  0.509  1.0
[/CIF]
.