data_[K6Sr3Hg3I18]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  K  0.8200  2.2000  1.5200
  Sr  0.9500  2.0000  1.3200
  Hg  2.0000  1.5000  1.2450
  I  2.6600  1.4000  1.2733
]
_symmetry_space_group_name_H-M [R3]
_cell_length_a [8.5777]
_cell_length_b [8.5777]
_cell_length_c [21.5289]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [120.0000]
_symmetry_Int_Tables_number [146]
_chemical_formula_structural [K2SrHgI6]
_chemical_formula_sum '[K6 Sr3 Hg3 I18]'
_cell_volume [1371.8103]
_cell_formula_units_Z [3]
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  3  0.0000  0.0000  0.0312  1
  K  K1  3  0.0000  0.0000  0.5311  1
  Sr  Sr2  3  0.0000  0.0000  0.8183  1
  Hg  Hg3  3  0.0000  0.0000  0.3183  1
  I  I4  9  0.0243  0.6189  0.0749  1
  I  I5  9  0.0642  0.3365  0.9127  1
]