data_[K6Cu8Se8]
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
  Se  2.5500  1.1500  1.0133
]
_symmetry_space_group_name_H-M [I-43m]
_cell_length_a [7.8903]
_cell_length_b [7.8903]
_cell_length_c [7.8903]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [217]
_chemical_formula_structural [K3(CuSe)4]
_chemical_formula_sum '[K6 Cu8 Se8]'
_cell_volume [491.2230]
_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  6  0.0000  0.0000  0.5000  1.0
  Cu  Cu1  8  0.1279  0.1279  0.1279  1.0
  Se  Se2  8  0.1831  0.1831  0.8169  1.0
]