data_FeCu
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   2.5
_cell_length_b   4.19
_cell_length_c   4.58
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   FeCu
_chemical_formula_sum   'Fe2 Cu2'
_cell_volume   48.07
_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  0.25  0.1  0.21  1.0
  Fe  Fe3  1  0.0  0.0  0.38  1.0
  Cu  Cu0  1  0.25  0.0  0.67  1.0
  Cu  Cu1  1  0.0  0.1  0.91  1.0

data_FeCu
_symmetry_space_group_name_H-M   P-1
_cell_length_a   2.5
_cell_length_b   4.19
_cell_length_c   4.58
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   2
_chemical_formula_structural   FeCu
_chemical_formula_sum   'Fe2 Cu2'
_cell_volume   48.07
_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  0.13  0.05  0.92  1.0
  Cu  Cu1  2  0.13  0.95  0.38  1.0

Fe Fe Cu Cu