data_[K6Na3Er3I18]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  K  0.8200  2.2000  1.5200
  Na  0.9300  1.8000  1.1600
  Er  1.2400  1.7500  1.0300
  I  2.6600  1.4000  1.2733
]
_symmetry_space_group_name_H-M [R3]
_cell_length_a [8.4990]
_cell_length_b [8.4990]
_cell_length_c [21.3624]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [120.0000]
_symmetry_Int_Tables_number [146]
_chemical_formula_structural [K2NaErI6]
_chemical_formula_sum '[K6 Na3 Er3 I18]'
_cell_volume [1336.3357]
_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  0.4637  1
  K  K1  3  0.0000  0.0000  0.9707  1
  Na  Na2  3  0.0000  0.0000  0.1812  1
  Er  Er3  3  0.0000  0.0000  0.6765  1
  I  I4  9  0.0117  0.4113  0.4225  1
  I  I5  9  0.0779  0.7233  0.2595  1
]