data_[K4Hg2Se2]
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
  Se  2.5500  1.1500  1.0133
]
_symmetry_space_group_name_H-M [Cm]
_cell_length_a [12.3496]
_cell_length_b [4.3044]
_cell_length_c [5.3306]
_cell_angle_alpha [90.0000]
_cell_angle_beta [109.5961]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [8]
_chemical_formula_structural [K2HgSe]
_chemical_formula_sum '[K4 Hg2 Se2]'
_cell_volume [266.9492]
_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  2  0.2892  0.5000  0.3097  1
  K  K1  2  0.4860  0.5000  0.9753  1
  Hg  Hg2  2  0.2052  0.0000  0.7287  1
  Se  Se3  2  0.0196  0.5000  0.4863  1
]