data_[Na6Mg2Hg2]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Na  0.9300  1.8000  1.1600
  Mg  1.3100  1.5000  0.8600
  Hg  2.0000  1.5000  1.2450
]
_symmetry_space_group_name_H-M [Amm2]
_cell_length_a [3.3102]
_cell_length_b [5.7997]
_cell_length_c [16.6347]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [38]
_chemical_formula_structural [Na3MgHg]
_chemical_formula_sum '[Na6 Mg2 Hg2]'
_cell_volume [319.3509]
_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  0.5000  0.2488  0.6061  1
  Na  Na1  2  0.0000  0.0000  0.7841  1
  Mg  Mg2  2  0.0000  0.0000  0.4336  1
  Hg  Hg3  2  0.5000  0.0000  0.9420  1
]