data_[Al18Cu21]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Al  1.6100  1.2500  0.6750
  Cu  1.9000  1.3500  0.8200
]
_symmetry_space_group_name_H-M [R-3m]
_cell_length_a [4.9090]
_cell_length_b [4.9090]
_cell_length_c [25.2484]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [120.0000]
_symmetry_Int_Tables_number [166]
_chemical_formula_structural [Al6Cu7]
_chemical_formula_sum '[Al18 Cu21]'
_cell_volume [526.9186]
_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
[
  Al  Al0  6  0.0000  0.0000  0.0491  1.0
  Al  Al1  6  0.0000  0.0000  0.1551  1.0
  Al  Al2  6  0.0000  0.0000  0.3328  1.0
  Cu  Cu3  18  0.0017  0.5008  0.9131  1.0
  Cu  Cu4  3  -0.0000  -0.0000  0.5000  1.0
]