data_FeC
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.14
_cell_length_b   5.14
_cell_length_c   5.14
_cell_angle_alpha   151.73
_cell_angle_beta   146.93
_cell_angle_gamma   44.05
_symmetry_Int_Tables_number   1
_chemical_formula_structural   FeC
_chemical_formula_sum   'Fe2 C2'
_cell_volume   34.92
_cell_formula_units_Z   2
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
  Fe  Fe2  1  0.0  0.19  0.15  1.0
  Fe  Fe3  1  0.25  0.27  0.62  1.0
  C  C0  1  0.25  0.73  0.19  1.0
  C  C1  1  0.0  0.73  0.57  1.0

data_FeC
_symmetry_space_group_name_H-M   P-1
_cell_length_a   2.51
_cell_length_b   2.92
_cell_length_c   5.14
_cell_angle_alpha   106.53
_cell_angle_beta   104.14
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   2
_chemical_formula_structural   FeC
_chemical_formula_sum   'Fe2 C2'
_cell_volume   34.92
_cell_formula_units_Z   2
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  '-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
  Fe  Fe0  2  0.46  0.2  0.07  1.0
  C  C1  2  0.0  0.31  0.18  1.0

Fe Fe C C
Fe Fe C C 0 3 o o o 0 3 o - - 0 1 o o o 1 2 o o + 1 2 o - o 