data_CuSi
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   2.71
_cell_length_b   4.48
_cell_length_c   4.63
_cell_angle_alpha   90.0
_cell_angle_beta   105.73
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   CuSi
_chemical_formula_sum   'Cu2 Si2'
_cell_volume   54.23
_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  Cu0  1  0.36  0.36  0.61  1.0
  Cu  Cu1  1  0.1  0.12  0.85  1.0
  Si  Si2  1  0.05  0.36  0.56  1.0
  Si  Si3  1  0.41  0.12  0.9  1.0

data_CuSi
_symmetry_space_group_name_H-M   P-1
_cell_length_a   2.71
_cell_length_b   4.48
_cell_length_c   4.63
_cell_angle_alpha   90.0
_cell_angle_beta   105.73
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   2
_chemical_formula_structural   CuSi
_chemical_formula_sum   'Cu2 Si2'
_cell_volume   54.23
_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  0.13  0.12  0.38  1.0
  Si  Si1  2  0.18  0.88  0.67  1.0

Cu Cu Si Si
Cu Cu Si Si 0 2 o o o 1 3 o o o 