data_[Na3Ac3As6O18]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Na  0.9300  1.8000  1.1600
  Ac  1.1000  1.9500  1.2600
  As  2.1800  1.1500  0.6600
  O  3.4400  0.6000  1.2600
]
_symmetry_space_group_name_H-M [R-3]
_cell_length_a [5.6660]
_cell_length_b [5.6660]
_cell_length_c [17.9095]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [120.0000]
_symmetry_Int_Tables_number [148]
_chemical_formula_structural [NaAc(AsO3)2]
_chemical_formula_sum '[Na3 Ac3 As6 O18]'
_cell_volume [497.9215]
_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  3  -0.0000  0.0000  0.5000  1
  Ac  Ac1  3  0.0000  0.0000  0.0000  1
  As  As2  6  0.0000  0.0000  0.2154  1
  O  O3  18  0.0017  0.7112  0.2486  1
]