data_[Na8Hg4F2]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Na  0.9300  1.8000  1.1600
  Hg  2.0000  1.5000  1.2450
  F  3.9800  0.5000  0.7050
]
_symmetry_space_group_name_H-M [I4/mmm]
_cell_length_a [4.6396]
_cell_length_b [4.6396]
_cell_length_c [16.0576]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [139]
_chemical_formula_structural [Na4Hg2F]
_chemical_formula_sum '[Na8 Hg4 F2]'
_cell_volume [345.6576]
_cell_formula_units_Z [2]
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  4  0.0000  0.0000  0.1617  1
  Na  Na1  4  0.0000  0.5000  0.0000  1
  Hg  Hg2  4  0.0000  0.0000  0.3534  1
  F  F3  2  0.0000  0.0000  0.0000  1
]