data_[K6Fe3Si6O18]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  K  0.8200  2.2000  1.5200
  Fe  1.8300  1.4000  0.8525
  Si  1.9000  1.1000  0.5400
  O  3.4400  0.6000  1.2600
]
_symmetry_space_group_name_H-M [R-3m]
_cell_length_a [5.7416]
_cell_length_b [5.7416]
_cell_length_c [17.5518]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [120.0000]
_symmetry_Int_Tables_number [166]
_chemical_formula_structural [K2Fe(SiO3)2]
_chemical_formula_sum '[K6 Fe3 Si6 O18]'
_cell_volume [501.0866]
_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  6  0.0000  0.0000  0.2024  1
  Fe  Fe1  3  0.0000  0.0000  0.0000  1
  Si  Si2  6  0.0000  0.0000  0.4054  1
  O  O3  18  0.0147  0.5074  0.2588  1
]