data_[Cu24Ag3Se18]
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 [R-3]
_cell_length_a [6.7787]
_cell_length_b [6.7787]
_cell_length_c [21.4508]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [120.0000]
_symmetry_Int_Tables_number [148]
_chemical_formula_structural [Cu8AgSe6]
_chemical_formula_sum '[Cu24 Ag3 Se18]'
_cell_volume [853.6342]
_cell_formula_units_Z [3]
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  18  0.0260  0.2623  0.1426  1
  Cu  Cu1  6  0.0000  0.0000  0.4358  1
  Ag  Ag2  3  0.0000  0.0000  0.0000  1
  Se  Se3  18  0.0091  0.6858  0.7445  1
]