data_[Fe6As6Se18]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Fe  1.8300  1.4000  0.8525
  As  2.1800  1.1500  0.6600
  Se  2.5500  1.1500  1.0133
]
_symmetry_space_group_name_H-M [R-3]
_cell_length_a [6.4298]
_cell_length_b [6.4298]
_cell_length_c [18.9652]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [120.0000]
_symmetry_Int_Tables_number [148]
_chemical_formula_structural [FeAsSe3]
_chemical_formula_sum '[Fe6 As6 Se18]'
_cell_volume [679.0260]
_cell_formula_units_Z [6]
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
[
  Fe  Fe0  6  0.0000  0.0000  0.1675  1
  As  As1  6  0.0000  0.0000  0.4356  1
  Se  Se2  18  0.0020  0.6032  0.4250  1
]