data_[Na2Sr4Ca8]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Na  0.9300  1.8000  1.1600
  Sr  0.9500  2.0000  1.3200
  Ca  1.0000  1.8000  1.1400
]
_symmetry_space_group_name_H-M [C2/m]
_cell_length_a [18.8145]
_cell_length_b [3.8328]
_cell_length_c [9.9310]
_cell_angle_alpha [90.0000]
_cell_angle_beta [117.0132]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [12]
_chemical_formula_structural [Na(SrCa2)2]
_chemical_formula_sum '[Na2 Sr4 Ca8]'
_cell_volume [638.0123]
_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  0.0000  0.0000  0.0000  1.0
  Sr  Sr1  4  0.2180  0.0000  0.1496  1.0
  Ca  Ca2  4  0.0711  0.0000  0.7015  1.0
  Ca  Ca3  4  0.1373  0.5000  0.4204  1.0
]