data_[Na4Hg2C4O12]
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
  C  2.5500  0.7000  0.3000
  O  3.4400  0.6000  1.2600
]
_symmetry_space_group_name_H-M [C2/m]
_cell_length_a [9.2849]
_cell_length_b [5.2546]
_cell_length_c [6.3085]
_cell_angle_alpha [90.0000]
_cell_angle_beta [116.1214]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [12]
_chemical_formula_structural [Na2Hg(CO3)2]
_chemical_formula_sum '[Na4 Hg2 C4 O12]'
_cell_volume [276.3435]
_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  0.1938  0.5000  0.1650  1
  Hg  Hg1  2  0.0000  0.5000  0.5000  1
  C  C2  4  0.0255  0.0000  0.2617  1
  O  O3  8  0.0598  0.2128  0.8053  1
  O  O4  4  0.1760  0.0000  0.3814  1
]