The crystal structure described by Nd2Fe17C crystallizes in the monoclinic C2/m space group. Nd(1) is bonded in a distorted single-bond geometry to one Fe(1), one Fe(6), two equivalent Fe(7), four equivalent Fe(5), six equivalent Fe(3), and one C(1) atom. There are seven inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a 14-coordinate geometry to one Nd(1), one Fe(1), one Fe(2), one Fe(6), two equivalent Fe(3), two equivalent Fe(4), two equivalent Fe(7), and four equivalent Fe(5) atoms. In the second Fe site, Fe(2) is bonded in a single-bond geometry to one Fe(1), two equivalent Fe(3), two equivalent Fe(5), two equivalent Fe(7), and one C(1) atom. In the third Fe site, Fe(3) is bonded to three equivalent Nd(1), one Fe(1), one Fe(2), one Fe(3), one Fe(4), one Fe(6), one Fe(7), and three equivalent Fe(5) atoms to form FeNd3Fe9 cuboctahedra that share  a cornercorner with one Fe(6)Nd2Fe10 cuboctahedra, corners with four equivalent Fe(7)Nd2Fe10 cuboctahedra, corners with five equivalent Fe(5)Nd2Fe10 cuboctahedra, corners with seven equivalent Fe(3)Nd3Fe9 cuboctahedra, corners with two equivalent C(1)Nd2Fe4 octahedra,  an edgeedge with one Fe(5)Nd2Fe10 cuboctahedra,  an edgeedge with one Fe(6)Nd2Fe10 cuboctahedra, edges with two equivalent Fe(7)Nd2Fe10 cuboctahedra, edges with three equivalent Fe(3)Nd3Fe9 cuboctahedra,  a faceface with one Fe(6)Nd2Fe10 cuboctahedra, faces with two equivalent Fe(7)Nd2Fe10 cuboctahedra, faces with four equivalent Fe(3)Nd3Fe9 cuboctahedra, faces with seven equivalent Fe(5)Nd2Fe10 cuboctahedra, and  a faceface with one C(1)Nd2Fe4 octahedra. The corner-sharing octahedral tilt angles range from 65-70°. In the fourth Fe site, Fe(4) is bonded in a single-bond geometry to two equivalent Fe(1), two equivalent Fe(3), two equivalent Fe(5), two equivalent Fe(7), and one C(1) atom. In the fifth Fe site, Fe(5) is bonded to two equivalent Nd(1), one Fe(2), one Fe(4), one Fe(5), one Fe(6), one Fe(7), two equivalent Fe(1), and three equivalent Fe(3) atoms to form distorted FeNd2Fe10 cuboctahedra that share  a cornercorner with one Fe(6)Nd2Fe10 cuboctahedra, corners with three equivalent Fe(7)Nd2Fe10 cuboctahedra, corners with five equivalent Fe(3)Nd3Fe9 cuboctahedra, corners with seven equivalent Fe(5)Nd2Fe10 cuboctahedra, corners with two equivalent C(1)Nd2Fe4 octahedra,  an edgeedge with one Fe(5)Nd2Fe10 cuboctahedra,  an edgeedge with one Fe(6)Nd2Fe10 cuboctahedra,  an edgeedge with one Fe(7)Nd2Fe10 cuboctahedra,  an edgeedge with one Fe(3)Nd3Fe9 cuboctahedra,  an edgeedge with one C(1)Nd2Fe4 octahedra,  a faceface with one Fe(6)Nd2Fe10 cuboctahedra, faces with three equivalent Fe(7)Nd2Fe10 cuboctahedra, faces with four equivalent Fe(5)Nd2Fe10 cuboctahedra, and faces with seven equivalent Fe(3)Nd3Fe9 cuboctahedra. The corner-sharing octahedral tilt angles range from 24-30°. In the sixth Fe site, Fe(6) is bonded to two equivalent Nd(1), two equivalent Fe(1), four equivalent Fe(3), and four equivalent Fe(5) atoms to form FeNd2Fe10 cuboctahedra that share corners with four equivalent Fe(5)Nd2Fe10 cuboctahedra, corners with four equivalent Fe(7)Nd2Fe10 cuboctahedra, corners with four equivalent Fe(3)Nd3Fe9 cuboctahedra, corners with two equivalent C(1)Nd2Fe4 octahedra, edges with four equivalent Fe(5)Nd2Fe10 cuboctahedra, edges with four equivalent Fe(3)Nd3Fe9 cuboctahedra, faces with four equivalent Fe(5)Nd2Fe10 cuboctahedra, faces with four equivalent Fe(7)Nd2Fe10 cuboctahedra, and faces with four equivalent Fe(3)Nd3Fe9 cuboctahedra. The corner-sharing octahedral tilt angles are 45°. In the seventh Fe site, Fe(7) is bonded to two equivalent Nd(1), two equivalent Fe(1), two equivalent Fe(2), two equivalent Fe(3), two equivalent Fe(4), and two equivalent Fe(5) atoms to form distorted FeNd2Fe10 cuboctahedra that share corners with two equivalent Fe(6)Nd2Fe10 cuboctahedra, corners with two equivalent Fe(7)Nd2Fe10 cuboctahedra, corners with six equivalent Fe(5)Nd2Fe10 cuboctahedra, corners with eight equivalent Fe(3)Nd3Fe9 cuboctahedra, edges with two equivalent Fe(5)Nd2Fe10 cuboctahedra, edges with four equivalent Fe(3)Nd3Fe9 cuboctahedra, faces with two equivalent Fe(6)Nd2Fe10 cuboctahedra, faces with two equivalent Fe(7)Nd2Fe10 cuboctahedra, faces with four equivalent Fe(3)Nd3Fe9 cuboctahedra, faces with six equivalent Fe(5)Nd2Fe10 cuboctahedra, and faces with two equivalent C(1)Nd2Fe4 octahedra. C(1) is bonded to two equivalent Nd(1), two equivalent Fe(2), and two equivalent Fe(4) atoms to form CNd2Fe4 octahedra that share corners with two equivalent Fe(6)Nd2Fe10 cuboctahedra, corners with eight equivalent Fe(5)Nd2Fe10 cuboctahedra, corners with eight equivalent Fe(3)Nd3Fe9 cuboctahedra, edges with four equivalent Fe(5)Nd2Fe10 cuboctahedra, faces with four equivalent Fe(7)Nd2Fe10 cuboctahedra, and faces with four equivalent Fe(3)Nd3Fe9 cuboctahedra. is represented by the Crystallographic Information File (CIF) [CIF]
data_Nd2Fe17C
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.497
_cell_length_b   6.497
_cell_length_c   6.509
_cell_angle_alpha   83.840
_cell_angle_beta   83.840
_cell_angle_gamma   83.478
_symmetry_Int_Tables_number   1
_cell_volume   270.090
_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
  Nd  Nd0  1  0.661  0.661  0.648  1.0
  Nd  Nd1  1  0.339  0.339  0.352  1.0
  Fe  Fe2  1  0.904  0.904  0.903  1.0
  Fe  Fe3  1  0.096  0.096  0.097  1.0
  Fe  Fe4  1  0.343  0.343  0.852  1.0
  Fe  Fe5  1  0.341  0.850  0.342  1.0
  Fe  Fe6  1  0.850  0.341  0.342  1.0
  Fe  Fe7  1  0.657  0.657  0.148  1.0
  Fe  Fe8  1  0.659  0.150  0.658  1.0
  Fe  Fe9  1  0.150  0.659  0.658  1.0
  Fe  Fe10  1  0.286  0.714  0.000  1.0
  Fe  Fe11  1  0.714  0.001  0.286  1.0
  Fe  Fe12  1  0.999  0.286  0.714  1.0
  Fe  Fe13  1  0.286  0.999  0.714  1.0
  Fe  Fe14  1  0.001  0.714  0.286  1.0
  Fe  Fe15  1  0.714  0.286  0.000  1.0
  Fe  Fe16  1  0.000  0.000  0.500  1.0
  Fe  Fe17  1  0.000  0.500  0.000  1.0
  Fe  Fe18  1  0.500  0.000  0.000  1.0
  C  C19  1  0.500  0.500  0.000  1.0
[/CIF]
.
The crystal structure described by Nd2Fe17C crystallizes in the monoclinic C2/m space group. Nd(1) is bonded in a distorted single-bond geometry to one Fe(1), one Fe(6), two equivalent Fe(7), four equivalent Fe(5), six equivalent Fe(3), and one C(1) atom. There are seven inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a 14-coordinate geometry to one Nd(1), one Fe(1), one Fe(2), one Fe(6), two equivalent Fe(3), two equivalent Fe(4), two equivalent Fe(7), and four equivalent Fe(5) atoms. In the second Fe site, Fe(2) is bonded in a single-bond geometry to one Fe(1), two equivalent Fe(3), two equivalent Fe(5), two equivalent Fe(7), and one C(1) atom. In the third Fe site, Fe(3) is bonded to three equivalent Nd(1), one Fe(1), one Fe(2), one Fe(3), one Fe(4), one Fe(6), one Fe(7), and three equivalent Fe(5) atoms to form FeNd3Fe9 cuboctahedra that share  a cornercorner with one Fe(6)Nd2Fe10 cuboctahedra, corners with four equivalent Fe(7)Nd2Fe10 cuboctahedra, corners with five equivalent Fe(5)Nd2Fe10 cuboctahedra, corners with seven equivalent Fe(3)Nd3Fe9 cuboctahedra, corners with two equivalent C(1)Nd2Fe4 octahedra,  an edgeedge with one Fe(5)Nd2Fe10 cuboctahedra,  an edgeedge with one Fe(6)Nd2Fe10 cuboctahedra, edges with two equivalent Fe(7)Nd2Fe10 cuboctahedra, edges with three equivalent Fe(3)Nd3Fe9 cuboctahedra,  a faceface with one Fe(6)Nd2Fe10 cuboctahedra, faces with two equivalent Fe(7)Nd2Fe10 cuboctahedra, faces with four equivalent Fe(3)Nd3Fe9 cuboctahedra, faces with seven equivalent Fe(5)Nd2Fe10 cuboctahedra, and  a faceface with one C(1)Nd2Fe4 octahedra. The corner-sharing octahedral tilt angles range from 65-70°. In the fourth Fe site, Fe(4) is bonded in a single-bond geometry to two equivalent Fe(1), two equivalent Fe(3), two equivalent Fe(5), two equivalent Fe(7), and one C(1) atom. In the fifth Fe site, Fe(5) is bonded to two equivalent Nd(1), one Fe(2), one Fe(4), one Fe(5), one Fe(6), one Fe(7), two equivalent Fe(1), and three equivalent Fe(3) atoms to form distorted FeNd2Fe10 cuboctahedra that share  a cornercorner with one Fe(6)Nd2Fe10 cuboctahedra, corners with three equivalent Fe(7)Nd2Fe10 cuboctahedra, corners with five equivalent Fe(3)Nd3Fe9 cuboctahedra, corners with seven equivalent Fe(5)Nd2Fe10 cuboctahedra, corners with two equivalent C(1)Nd2Fe4 octahedra,  an edgeedge with one Fe(5)Nd2Fe10 cuboctahedra,  an edgeedge with one Fe(6)Nd2Fe10 cuboctahedra,  an edgeedge with one Fe(7)Nd2Fe10 cuboctahedra,  an edgeedge with one Fe(3)Nd3Fe9 cuboctahedra,  an edgeedge with one C(1)Nd2Fe4 octahedra,  a faceface with one Fe(6)Nd2Fe10 cuboctahedra, faces with three equivalent Fe(7)Nd2Fe10 cuboctahedra, faces with four equivalent Fe(5)Nd2Fe10 cuboctahedra, and faces with seven equivalent Fe(3)Nd3Fe9 cuboctahedra. The corner-sharing octahedral tilt angles range from 24-30°. In the sixth Fe site, Fe(6) is bonded to two equivalent Nd(1), two equivalent Fe(1), four equivalent Fe(3), and four equivalent Fe(5) atoms to form FeNd2Fe10 cuboctahedra that share corners with four equivalent Fe(5)Nd2Fe10 cuboctahedra, corners with four equivalent Fe(7)Nd2Fe10 cuboctahedra, corners with four equivalent Fe(3)Nd3Fe9 cuboctahedra, corners with two equivalent C(1)Nd2Fe4 octahedra, edges with four equivalent Fe(5)Nd2Fe10 cuboctahedra, edges with four equivalent Fe(3)Nd3Fe9 cuboctahedra, faces with four equivalent Fe(5)Nd2Fe10 cuboctahedra, faces with four equivalent Fe(7)Nd2Fe10 cuboctahedra, and faces with four equivalent Fe(3)Nd3Fe9 cuboctahedra. The corner-sharing octahedral tilt angles are 45°. In the seventh Fe site, Fe(7) is bonded to two equivalent Nd(1), two equivalent Fe(1), two equivalent Fe(2), two equivalent Fe(3), two equivalent Fe(4), and two equivalent Fe(5) atoms to form distorted FeNd2Fe10 cuboctahedra that share corners with two equivalent Fe(6)Nd2Fe10 cuboctahedra, corners with two equivalent Fe(7)Nd2Fe10 cuboctahedra, corners with six equivalent Fe(5)Nd2Fe10 cuboctahedra, corners with eight equivalent Fe(3)Nd3Fe9 cuboctahedra, edges with two equivalent Fe(5)Nd2Fe10 cuboctahedra, edges with four equivalent Fe(3)Nd3Fe9 cuboctahedra, faces with two equivalent Fe(6)Nd2Fe10 cuboctahedra, faces with two equivalent Fe(7)Nd2Fe10 cuboctahedra, faces with four equivalent Fe(3)Nd3Fe9 cuboctahedra, faces with six equivalent Fe(5)Nd2Fe10 cuboctahedra, and faces with two equivalent C(1)Nd2Fe4 octahedra. C(1) is bonded to two equivalent Nd(1), two equivalent Fe(2), and two equivalent Fe(4) atoms to form CNd2Fe4 octahedra that share corners with two equivalent Fe(6)Nd2Fe10 cuboctahedra, corners with eight equivalent Fe(5)Nd2Fe10 cuboctahedra, corners with eight equivalent Fe(3)Nd3Fe9 cuboctahedra, edges with four equivalent Fe(5)Nd2Fe10 cuboctahedra, faces with four equivalent Fe(7)Nd2Fe10 cuboctahedra, and faces with four equivalent Fe(3)Nd3Fe9 cuboctahedra. is represented by the Crystallographic Information File (CIF) [CIF]
data_Nd2Fe17C
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.497
_cell_length_b   6.497
_cell_length_c   6.509
_cell_angle_alpha   83.840
_cell_angle_beta   83.840
_cell_angle_gamma   83.478
_symmetry_Int_Tables_number   1
_cell_volume   270.090
_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
  Nd  Nd0  1  0.661  0.661  0.648  1.0
  Nd  Nd1  1  0.339  0.339  0.352  1.0
  Fe  Fe2  1  0.904  0.904  0.903  1.0
  Fe  Fe3  1  0.096  0.096  0.097  1.0
  Fe  Fe4  1  0.343  0.343  0.852  1.0
  Fe  Fe5  1  0.341  0.850  0.342  1.0
  Fe  Fe6  1  0.850  0.341  0.342  1.0
  Fe  Fe7  1  0.657  0.657  0.148  1.0
  Fe  Fe8  1  0.659  0.150  0.658  1.0
  Fe  Fe9  1  0.150  0.659  0.658  1.0
  Fe  Fe10  1  0.286  0.714  0.000  1.0
  Fe  Fe11  1  0.714  0.001  0.286  1.0
  Fe  Fe12  1  0.999  0.286  0.714  1.0
  Fe  Fe13  1  0.286  0.999  0.714  1.0
  Fe  Fe14  1  0.001  0.714  0.286  1.0
  Fe  Fe15  1  0.714  0.286  0.000  1.0
  Fe  Fe16  1  0.000  0.000  0.500  1.0
  Fe  Fe17  1  0.000  0.500  0.000  1.0
  Fe  Fe18  1  0.500  0.000  0.000  1.0
  C  C19  1  0.500  0.500  0.000  1.0
[/CIF]
.