data_[Na4Si4As8]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Na  0.9300  1.8000  1.1600
  Si  1.9000  1.1000  0.5400
  As  2.1800  1.1500  0.6600
]
_symmetry_space_group_name_H-M [P2/c]
_cell_length_a [5.8704]
_cell_length_b [6.8238]
_cell_length_c [11.6479]
_cell_angle_alpha [90.0000]
_cell_angle_beta [119.3258]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [13]
_chemical_formula_structural [NaSiAs2]
_chemical_formula_sum '[Na4 Si4 As8]'
_cell_volume [406.8073]
_cell_formula_units_Z [4]
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  0.3187  0.2897  0.8709  1.0
  Si  Si1  4  0.2154  0.0955  0.1118  1.0
  As  As2  4  0.1344  0.2441  0.5750  1.0
  As  As3  4  0.3708  0.2604  0.3174  1.0
]