data_[Na6Cr6O18]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Na  0.9300  1.8000  1.1600
  Cr  1.6600  1.4000  0.9400
  O  3.4400  0.6000  1.2600
]
_symmetry_space_group_name_H-M [R-3]
_cell_length_a [5.7805]
_cell_length_b [5.7805]
_cell_length_c [17.1257]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [120.0000]
_symmetry_Int_Tables_number [148]
_chemical_formula_structural [NaCrO3]
_chemical_formula_sum '[Na6 Cr6 O18]'
_cell_volume [495.5823]
_cell_formula_units_Z [6]
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  6  0.0000  0.0000  0.1601  1
  Cr  Cr1  6  0.0000  0.0000  0.4284  1
  O  O2  18  0.0089  0.7208  0.4222  1
]