data_[Cu2Se2S2]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Cu  1.9000  1.3500  0.8200
  Se  2.5500  1.1500  1.0133
  S  2.5800  1.0000  0.8800
]
_symmetry_space_group_name_H-M [P2/m]
_cell_length_a [5.6481]
_cell_length_b [3.7897]
_cell_length_c [5.8180]
_cell_angle_alpha [90.0000]
_cell_angle_beta [93.0919]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [10]
_chemical_formula_structural [CuSeS]
_chemical_formula_sum '[Cu2 Se2 S2]'
_cell_volume [124.3526]
_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  0.0000  0.5000  0.0000  1
  Cu  Cu1  1  0.5000  0.0000  0.5000  1
  Se  Se2  2  0.1684  0.0000  0.8417  1
  S  S3  2  0.3477  0.5000  0.3478  1
]