data_[Na2Ca2Hg2Te4]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Na  0.9300  1.8000  1.1600
  Ca  1.0000  1.8000  1.1400
  Hg  2.0000  1.5000  1.2450
  Te  2.1000  1.4000  1.2933
]
_symmetry_space_group_name_H-M [Pccm]
_cell_length_a [6.1002]
_cell_length_b [7.1184]
_cell_length_c [8.0026]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [49]
_chemical_formula_structural [NaCaHgTe2]
_chemical_formula_sum '[Na2 Ca2 Hg2 Te4]'
_cell_volume [347.5026]
_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  0.2500  1
  Ca  Ca1  2  0.5000  0.0000  0.2500  1
  Hg  Hg2  2  0.0000  0.0000  0.0000  1
  Te  Te3  4  0.3421  0.3097  0.0000  1
]