data_[K2Cu2Ag4Se4]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  K  0.8200  2.2000  1.5200
  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 [Pmc2_1]
_cell_length_a [4.1968]
_cell_length_b [8.9423]
_cell_length_c [7.4685]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [26]
_chemical_formula_structural [KCu(AgSe)2]
_chemical_formula_sum '[K2 Cu2 Ag4 Se4]'
_cell_volume [280.2871]
_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
[
  K  K0  2  0.0000  0.4791  0.0296  1.0
  Cu  Cu1  2  0.5000  0.1907  0.5941  1.0
  Ag  Ag2  2  0.0000  0.1044  0.3440  1.0
  Ag  Ag3  2  0.5000  0.1122  0.0170  1.0
  Se  Se4  2  0.0000  0.1833  0.7636  1.0
  Se  Se5  2  0.5000  0.3018  0.2972  1.0
]