data_[Na18Fe3Sn6]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Na  0.9300  1.8000  1.1600
  Fe  1.8300  1.4000  0.8525
  Sn  1.9600  1.4500  0.8300
]
_symmetry_space_group_name_H-M [R-3m]
_cell_length_a [5.4426]
_cell_length_b [5.4426]
_cell_length_c [29.9478]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [120.0000]
_symmetry_Int_Tables_number [166]
_chemical_formula_structural [Na6FeSn2]
_chemical_formula_sum '[Na18 Fe3 Sn6]'
_cell_volume [768.2723]
_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
[
  Na  Na0  6  0.0000  0.0000  0.1924  1
  Na  Na1  6  0.0000  0.0000  0.3026  1
  Na  Na2  6  0.0000  0.0000  0.4172  1
  Fe  Fe3  3  0.0000  0.0000  0.0000  1
  Sn  Sn4  6  0.0000  0.0000  0.0853  1
]