data_[Np4Si12Ir20]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Np  1.3600  1.7500  1.0000
  Si  1.9000  1.1000  0.5400
  Ir  2.2000  1.3500  0.7650
]
_symmetry_space_group_name_H-M [Cmcm]
_cell_length_a [2.8916]
_cell_length_b [13.0443]
_cell_length_c [14.7811]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [63]
_chemical_formula_structural [NpSi3Ir5]
_chemical_formula_sum '[Np4 Si12 Ir20]'
_cell_volume [557.5365]
_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
[
  Np  Np0  4  0.0000  0.1871  0.2500  1
  Si  Si1  8  0.0000  0.3467  0.5382  1
  Si  Si2  4  0.0000  0.0997  0.7500  1
  Ir  Ir3  8  0.0000  0.1796  0.6003  1
  Ir  Ir4  8  0.0000  0.4881  0.6565  1
  Ir  Ir5  4  0.0000  0.0000  0.0000  1
]