data_[Na2Al2Si2]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Na  0.9300  1.8000  1.1600
  Al  1.6100  1.2500  0.6750
  Si  1.9000  1.1000  0.5400
]
_symmetry_space_group_name_H-M [P2_1/m]
_cell_length_a [4.0229]
_cell_length_b [4.0373]
_cell_length_c [8.0614]
_cell_angle_alpha [90.0000]
_cell_angle_beta [92.5996]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [11]
_chemical_formula_structural [NaAlSi]
_chemical_formula_sum '[Na2 Al2 Si2]'
_cell_volume [130.7950]
_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
[
  Na  Na0  2  0.2706  0.7500  0.1266  1
  Al  Al1  2  0.2126  0.7500  0.7064  1
  Si  Si2  2  0.2974  0.2500  0.4994  1
]