data_[Ca9O9]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Ca  1.0000  1.8000  1.1400
  O  3.4400  0.6000  1.2600
]
_symmetry_space_group_name_H-M [P6mm]
_cell_length_a [8.8230]
_cell_length_b [8.8230]
_cell_length_c [17.9288]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [120.0000]
_symmetry_Int_Tables_number [183]
_chemical_formula_structural [CaO]
_chemical_formula_sum '[Ca9 O9]'
_cell_volume [1208.6930]
_cell_formula_units_Z [9]
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
[
  Ca  Ca0  6  0.2067  0.4133  0.4425  1
  Ca  Ca1  3  0.0000  0.5000  0.5838  1
  O  O2  6  0.2167  0.4334  0.5554  1
  O  O3  3  0.0000  0.5000  0.4204  1
]