data_[Na4Si4]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Na  0.9300  1.8000  1.1600
  Si  1.9000  1.1000  0.5400
]
_symmetry_space_group_name_H-M [Cm]
_cell_length_a [10.5338]
_cell_length_b [3.8168]
_cell_length_c [5.8773]
_cell_angle_alpha [90.0000]
_cell_angle_beta [123.0589]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [8]
_chemical_formula_structural [NaSi]
_chemical_formula_sum '[Na4 Si4]'
_cell_volume [198.0450]
_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
[
  Na  Na0  2  0.1296  0.0000  0.6789  1
  Na  Na1  2  0.4965  0.0000  0.0451  1
  Si  Si2  2  0.3040  0.0000  0.3205  1
  Si  Si3  2  0.3146  0.5000  0.5589  1
]