data_[Na2Hg4P2Se8]
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
  P  2.1900  1.0000  0.5500
  Se  2.5500  1.1500  1.0133
]
_symmetry_space_group_name_H-M [I222]
_cell_length_a [6.9285]
_cell_length_b [7.5691]
_cell_length_c [8.8833]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [23]
_chemical_formula_structural [NaHg2PSe4]
_chemical_formula_sum '[Na2 Hg4 P2 Se8]'
_cell_volume [465.8599]
_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  2  0.0000  0.5000  0.5000  1
  Hg  Hg1  4  0.0000  0.2833  0.0000  1
  P  P2  2  0.0000  0.0000  0.5000  1
  Se  Se3  8  0.2021  0.2006  0.3376  1
]