data_[Si18H6]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Si  1.9000  1.1000  0.5400
  H  2.2000  0.2500  0.0000
]
_symmetry_space_group_name_H-M [R-3m]
_cell_length_a [3.8618]
_cell_length_b [3.8618]
_cell_length_c [35.5743]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [120.0000]
_symmetry_Int_Tables_number [166]
_chemical_formula_structural [Si3H]
_chemical_formula_sum '[Si18 H6]'
_cell_volume [459.4585]
_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
[
  Si  Si0  6  0.0000  0.0000  0.2338  1.0
  Si  Si1  6  0.0000  0.0000  0.3445  1.0
  Si  Si2  6  0.0000  0.0000  0.4114  1.0
  H  H3  6  0.0000  0.0000  0.1915  1.0
]