data_[Na12Fe4As8]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Na  0.9300  1.8000  1.1600
  Fe  1.8300  1.4000  0.8525
  As  2.1800  1.1500  0.6600
]
_symmetry_space_group_name_H-M [Ibam]
_cell_length_a [7.0698]
_cell_length_b [13.3174]
_cell_length_c [5.9458]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [72]
_chemical_formula_structural [Na3FeAs2]
_chemical_formula_sum '[Na12 Fe4 As8]'
_cell_volume [559.8096]
_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  8  0.1918  0.1835  0.5000  1.0
  Na  Na1  4  0.0000  0.5000  0.2500  1.0
  Fe  Fe2  4  0.0000  0.0000  0.2500  1.0
  As  As3  8  0.1938  0.9000  0.5000  1.0
]