data_[Si2F8]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Si  1.9000  1.1000  0.5400
  F  3.9800  0.5000  0.7050
]
_symmetry_space_group_name_H-M [Pmma]
_cell_length_a [7.2410]
_cell_length_b [17.7808]
_cell_length_c [4.9862]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [51]
_chemical_formula_structural [SiF4]
_chemical_formula_sum '[Si2 F8]'
_cell_volume [641.9763]
_cell_formula_units_Z [2]
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
[
  Si  Si0  2  0.2500  0.5000  0.4968  1
  F  F1  4  0.2500  0.4218  0.6502  1
  F  F2  2  0.0000  0.5000  0.5000  1
  F  F3  2  0.2500  0.5000  0.1786  1
]