data_[Na4Sr8Ca8]
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 [Ibam]
_cell_length_a [7.7466]
_cell_length_b [17.5471]
_cell_length_c [6.8299]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [72]
_chemical_formula_structural [Na(SrCa)2]
_chemical_formula_sum '[Na4 Sr8 Ca8]'
_cell_volume [928.3909]
_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  4  0.0000  0.5000  0.2500  1
  Sr  Sr1  8  0.1612  0.3143  0.5000  1
  Ca  Ca2  8  0.1364  0.0847  0.5000  1
]