data_Ar
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.53
_cell_length_b   3.53
_cell_length_c   5.75
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Ar
_chemical_formula_sum   Ar2
_cell_volume   62.08
_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
  Ar  Ar0  1  0.0  0.04  0.44  1.0
  Ar  Ar1  1  0.77  0.02  0.31  1.0

data_Ar
_symmetry_space_group_name_H-M   P-1
_cell_length_a   3.53
_cell_length_b   3.53
_cell_length_c   5.75
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   2
_chemical_formula_structural   Ar
_chemical_formula_sum   Ar2
_cell_volume   62.08
_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
  Ar  Ar0  2  0.38  0.99  0.94  1.0

Ar Ar
Ar Ar 0 1 - o o 