data_[Na3Cu2]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Na  0.9300  1.8000  1.1600
  Cu  1.9000  1.3500  0.8200
]
_symmetry_space_group_name_H-M [Pmm2]
_cell_length_a [2.9628]
_cell_length_b [19.9837]
_cell_length_c [7.1793]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [25]
_chemical_formula_structural [Na3Cu2]
_chemical_formula_sum '[Na3 Cu2]'
_cell_volume [425.0740]
_cell_formula_units_Z [1]
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
[
  Na  Na0  2  0.5000  0.3753  0.5994  1
  Na  Na1  1  0.0000  0.5000  0.1547  1
  Cu  Cu2  1  0.0000  0.5000  0.5427  1
  Cu  Cu3  1  0.5000  0.5000  0.8065  1
]