data_[Ba3Na6As6O21]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Ba  0.8900  2.1500  1.4900
  Na  0.9300  1.8000  1.1600
  As  2.1800  1.1500  0.6600
  O  3.4400  0.6000  1.2600
]
_symmetry_space_group_name_H-M [R32]
_cell_length_a [5.8732]
_cell_length_b [5.8732]
_cell_length_c [23.6436]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [120.0000]
_symmetry_Int_Tables_number [155]
_chemical_formula_structural [BaNa2As2O7]
_chemical_formula_sum '[Ba3 Na6 As6 O21]'
_cell_volume [706.3113]
_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
[
  Ba  Ba0  3  0.0000  0.0000  0.5000  1.0
  Na  Na1  6  0.0000  0.0000  0.2697  1.0
  As  As2  6  0.0000  0.0000  0.0755  1.0
  O  O3  18  0.0018  0.2804  0.0942  1.0
  O  O4  3  0.0000  0.0000  0.0000  1.0
]