data_[K4Ca2Hg4Se8]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  K  0.8200  2.2000  1.5200
  Ca  1.0000  1.8000  1.1400
  Hg  2.0000  1.5000  1.2450
  Se  2.5500  1.1500  1.0133
]
_symmetry_space_group_name_H-M [C2/m]
_cell_length_a [16.4828]
_cell_length_b [4.3518]
_cell_length_c [8.0126]
_cell_angle_alpha [90.0000]
_cell_angle_beta [108.8487]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [12]
_chemical_formula_structural [K2Ca(HgSe2)2]
_chemical_formula_sum '[K4 Ca2 Hg4 Se8]'
_cell_volume [543.9197]
_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  0.1233  0.0000  0.5586  1.0
  Ca  Ca1  2  0.0000  0.0000  0.0000  1.0
  Hg  Hg2  4  0.1651  0.5000  0.9917  1.0
  Se  Se3  4  0.0133  0.5000  0.7530  1.0
  Se  Se4  4  0.2081  0.0000  0.2063  1.0
]