data_[Na4Ca4C6O18]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Na  0.9300  1.8000  1.1600
  Ca  1.0000  1.8000  1.1400
  C  2.5500  0.7000  0.3000
  O  3.4400  0.6000  1.2600
]
_symmetry_space_group_name_H-M [Amm2]
_cell_length_a [5.0069]
_cell_length_b [11.1566]
_cell_length_c [7.1977]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [38]
_chemical_formula_structural [Na2Ca2(CO3)3]
_chemical_formula_sum '[Na4 Ca4 C6 O18]'
_cell_volume [402.0623]
_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  0.9259  1.0
  Na  Na1  2  0.5000  0.0000  0.6124  1.0
  Ca  Ca2  4  0.5000  0.2164  0.9986  1.0
  C  C3  4  0.0000  0.2041  0.6698  1.0
  C  C4  2  0.5000  0.0000  0.2257  1.0
  O  O5  8  0.2261  0.1544  0.7152  1.0
  O  O6  4  0.0000  0.1979  0.0745  1.0
  O  O7  4  0.5000  0.1015  0.3117  1.0
  O  O8  2  0.5000  0.0000  0.0418  1.0
]