data_[Fe8Se12]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Fe  1.8300  1.4000  0.8525
  Se  2.5500  1.1500  1.0133
]
_symmetry_space_group_name_H-M [P4mm]
_cell_length_a [7.9575]
_cell_length_b [7.9575]
_cell_length_c [18.7185]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [99]
_chemical_formula_structural [Fe2Se3]
_chemical_formula_sum '[Fe8 Se12]'
_cell_volume [1185.2813]
_cell_formula_units_Z [4]
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  4  0.0000  0.2126  0.4403  1
  Fe  Fe1  4  0.1531  0.5000  0.4865  1
  Se  Se2  4  0.0000  0.2847  0.5588  1
  Se  Se3  4  0.2733  0.5000  0.6065  1
  Se  Se4  4  0.2849  0.2849  0.4079  1
]