data_[Na1Np2Hg1O8]
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
  Hg  2.0000  1.5000  1.2450
  O  3.4400  0.6000  1.2600
]
_symmetry_space_group_name_H-M [P-3]
_cell_length_a [6.0177]
_cell_length_b [6.0177]
_cell_length_c [6.2086]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [120.0000]
_symmetry_Int_Tables_number [147]
_chemical_formula_structural [NaNp2HgO8]
_chemical_formula_sum '[Na1 Np2 Hg1 O8]'
_cell_volume [194.7101]
_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  1  0.0000  0.0000  0.0000  1
  Np  Np1  2  0.3333  0.6667  0.9377  1
  Hg  Hg2  1  0.0000  0.0000  0.5000  1
  O  O3  6  0.0640  0.3909  0.1371  1
  O  O4  2  0.3333  0.6667  0.6424  1
]