data_[Na3Np3Ni6O18]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Na  0.9300  1.8000  1.1600
  Np  1.3600  1.7500  1.0000
  Ni  1.9100  1.3500  0.7400
  O  3.4400  0.6000  1.2600
]
_symmetry_space_group_name_H-M [R3]
_cell_length_a [5.3464]
_cell_length_b [5.3464]
_cell_length_c [14.6982]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [120.0000]
_symmetry_Int_Tables_number [146]
_chemical_formula_structural [NaNp(NiO3)2]
_chemical_formula_sum '[Na3 Np3 Ni6 O18]'
_cell_volume [363.8440]
_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  0.4904  1
  Np  Np1  3  0.0000  0.0000  0.0073  1
  Ni  Ni2  3  0.0000  0.0000  0.2065  1
  Ni  Ni3  3  0.0000  0.0000  0.6914  1
  O  O4  9  0.0046  0.3362  0.2729  1
  O  O5  9  0.0670  0.7082  0.7621  1
]