data_[Cu2Ag2Se2]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Cu  1.9000  1.3500  0.8200
  Ag  1.9300  1.6000  1.0867
  Se  2.5500  1.1500  1.0133
]
_symmetry_space_group_name_H-M [P1]
_cell_length_a [4.3011]
_cell_length_b [4.8465]
_cell_length_c [6.4524]
_cell_angle_alpha [84.0372]
_cell_angle_beta [78.4865]
_cell_angle_gamma [70.5886]
_symmetry_Int_Tables_number [1]
_chemical_formula_structural [CuAgSe]
_chemical_formula_sum '[Cu2 Ag2 Se2]'
_cell_volume [124.1991]
_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  0.2269  0.8793  0.4447  1
  Cu  Cu1  1  0.8237  0.8353  0.1237  1
  Ag  Ag2  1  0.3369  0.0168  0.8610  1
  Ag  Ag3  1  0.4762  0.4520  0.0943  1
  Se  Se4  1  0.0501  0.5982  0.8077  1
  Se  Se5  1  0.6461  0.1074  0.4212  1
]