data_[K2Hg2Se4]
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 [12.5977]
_cell_length_b [2.9556]
_cell_length_c [5.7635]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0679]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [8]
_chemical_formula_structural [KHgSe2]
_chemical_formula_sum '[K2 Hg2 Se4]'
_cell_volume [214.5924]
_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  0.2458  0.5000  0.8665  1
  Hg  Hg1  2  0.4813  0.0000  0.4018  1
  Se  Se2  2  0.0093  0.0000  0.8667  1
  Se  Se3  2  0.2636  0.0000  0.3651  1
]