data_[Na4As2O8]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  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 [C2/m]
_cell_length_a [10.7455]
_cell_length_b [2.8695]
_cell_length_c [6.1941]
_cell_angle_alpha [90.0000]
_cell_angle_beta [120.4618]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [12]
_chemical_formula_structural [Na2AsO4]
_chemical_formula_sum '[Na4 As2 O8]'
_cell_volume [164.6263]
_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  4  0.1536  0.5000  0.6754  1
  As  As1  2  0.0000  0.0000  0.0000  1
  O  O2  4  0.0312  0.0000  0.3134  1
  O  O3  4  0.1368  0.5000  0.0845  1
]