data_[Na21Sr36Ca3]
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 [R-3]
_cell_length_a [17.5429]
_cell_length_b [17.5429]
_cell_length_c [10.9476]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [120.0000]
_symmetry_Int_Tables_number [148]
_chemical_formula_structural [Na7Sr12Ca]
_chemical_formula_sum '[Na21 Sr36 Ca3]'
_cell_volume [2917.7647]
_cell_formula_units_Z [3]
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  18  0.0058  0.8643  0.2404  1
  Na  Na1  3  0.0000  0.0000  0.5000  1
  Sr  Sr2  18  0.0248  0.7809  0.8961  1
  Sr  Sr3  18  0.0663  0.4815  0.1384  1
  Ca  Ca4  3  0.0000  0.0000  0.0000  1
]