data_FeC2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.96
_cell_length_b   2.51
_cell_length_c   6.56
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   FeC2
_chemical_formula_sum   'Fe4 C8'
_cell_volume   114.68
_cell_formula_units_Z   4
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  Fe8  1  0.07  0.88  0.63  1.0
  Fe  Fe9  1  0.41  0.63  0.35  1.0
  Fe  Fe10  1  0.55  0.88  0.21  1.0
  Fe  Fe11  1  0.89  0.63  0.93  1.0
  C  C0  1  0.69  0.88  0.79  1.0
  C  C1  1  0.75  0.63  0.07  1.0
  C  C2  1  0.21  0.88  0.5  1.0
  C  C3  1  0.27  0.63  0.78  1.0
  C  C4  1  0.32  0.88  0.68  1.0
  C  C5  1  0.12  0.63  0.4  1.0
  C  C6  1  0.84  0.88  0.17  1.0
  C  C7  1  0.64  0.63  0.88  1.0

data_FeC2
_symmetry_space_group_name_H-M   P-1
_cell_length_a   2.51
_cell_length_b   6.56
_cell_length_c   6.96
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   2
_chemical_formula_structural   FeC2
_chemical_formula_sum   'Fe4 C8'
_cell_volume   114.68
_cell_formula_units_Z   4
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  0.37  0.65  0.41  1.0
  Fe  Fe1  2  0.37  0.07  0.93  1.0
  C  C2  2  0.37  0.5  0.79  1.0
  C  C3  2  0.37  0.6  0.16  1.0
  C  C4  2  0.37  0.12  0.64  1.0
  C  C5  2  0.37  0.79  0.27  1.0

Fe Fe Fe Fe C C C C C C C C
Fe Fe Fe Fe C C C C C C C C 0 6 o o o 1 2 o o o 3 5 o o + 4 11 o o o 5 10 o o o 6 9 o o o 7 8 o o o 