data_[Na3Y6Np3O18]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Na  0.9300  1.8000  1.1600
  Y  1.2200  1.8000  1.0400
  Np  1.3600  1.7500  1.0000
  O  3.4400  0.6000  1.2600
]
_symmetry_space_group_name_H-M [R3]
_cell_length_a [5.8484]
_cell_length_b [5.8484]
_cell_length_c [15.3721]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [120.0000]
_symmetry_Int_Tables_number [146]
_chemical_formula_structural [NaY2NpO6]
_chemical_formula_sum '[Na3 Y6 Np3 O18]'
_cell_volume [455.3454]
_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
[
  Na  Na0  3  0.0000  0.0000  0.2015  1
  Y  Y1  3  0.0000  0.0000  0.4727  1
  Y  Y2  3  0.0000  0.0000  0.9830  1
  Np  Np3  3  0.0000  0.0000  0.6816  1
  O  O4  9  0.0211  0.3432  0.7443  1
  O  O5  9  0.0266  0.7401  0.5890  1
]