data_CuAg
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   2.78
_cell_length_b   4.22
_cell_length_c   5.32
_cell_angle_alpha   90.0
_cell_angle_beta   105.08
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   CuAg
_chemical_formula_sum   'Cu2 Ag2'
_cell_volume   60.41
_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
  Cu  Cu2  1  0.17  0.06  0.22  1.0
  Cu  Cu3  1  0.23  0.17  0.92  1.0
  Ag  Ag0  1  0.66  0.17  0.33  1.0
  Ag  Ag1  1  0.74  0.06  0.8  1.0

data_CuAg
_symmetry_space_group_name_H-M   P-1
_cell_length_a   2.78
_cell_length_b   4.22
_cell_length_c   5.32
_cell_angle_alpha   90.0
_cell_angle_beta   105.08
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   2
_chemical_formula_structural   CuAg
_chemical_formula_sum   'Cu2 Ag2'
_cell_volume   60.41
_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
  Cu  Cu0  2  0.03  0.06  0.85  1.0
  Ag  Ag1  2  0.46  0.06  0.27  1.0

Cu Cu Ag Ag
Cu Cu Ag Ag 0 2 - o o 0 2 o o o 0 1 o o - 1 3 - o o 1 3 o o o 