data_Cu2S
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.84
_cell_length_b   3.84
_cell_length_c   7.1
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Cu2S
_chemical_formula_sum   'Cu4 S2'
_cell_volume   90.51
_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  0.92  0.11  0.97  1.0
  Cu  Cu1  1  0.0  0.22  0.52  1.0
  Cu  Cu2  1  0.0  0.22  0.13  1.0
  Cu  Cu3  1  0.92  0.11  0.58  1.0
  S  S4  1  0.92  0.11  0.32  1.0
  S  S5  1  0.0  0.22  0.77  1.0

data_Cu2S
_symmetry_space_group_name_H-M   P-1
_cell_length_a   3.84
_cell_length_b   3.84
_cell_length_c   7.1
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   2
_chemical_formula_structural   Cu2S
_chemical_formula_sum   'Cu4 S2'
_cell_volume   90.51
_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  0.46  0.95  0.92  1.0
  Cu  Cu1  2  0.46  0.95  0.53  1.0
  S  S2  2  0.46  0.95  0.27  1.0

Cu Cu Cu Cu S S