data_[K4Hg2Pb2Se8]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  K  0.8200  2.2000  1.5200
  Hg  2.0000  1.5000  1.2450
  Pb  2.3300  1.8000  1.1225
  Se  2.5500  1.1500  1.0133
]
_symmetry_space_group_name_H-M [I-42m]
_cell_length_a [8.2722]
_cell_length_b [8.2722]
_cell_length_c [7.1906]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [121]
_chemical_formula_structural [K2HgPbSe4]
_chemical_formula_sum '[K4 Hg2 Pb2 Se8]'
_cell_volume [492.0507]
_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
[
  K  K0  4  0.0000  0.5000  0.0000  1.0
  Hg  Hg1  2  0.0000  0.0000  0.0000  1.0
  Pb  Pb2  2  0.0000  0.0000  0.5000  1.0
  Se  Se3  8  0.1746  0.1746  0.7408  1.0
]