data_[Na4Ag4As8Se16]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Na  0.9300  1.8000  1.1600
  Ag  1.9300  1.6000  1.0867
  As  2.1800  1.1500  0.6600
  Se  2.5500  1.1500  1.0133
]
_symmetry_space_group_name_H-M [Fmm2]
_cell_length_a [8.7048]
_cell_length_b [9.4140]
_cell_length_c [11.1475]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [42]
_chemical_formula_structural [NaAg(AsSe2)2]
_chemical_formula_sum '[Na4 Ag4 As8 Se16]'
_cell_volume [913.5036]
_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  0.0000  0.0000  0.0078  1
  Ag  Ag1  4  0.0000  0.0000  0.5028  1
  As  As2  8  0.2500  0.2500  0.2568  1
  Se  Se3  8  0.0000  0.2364  0.6385  1
  Se  Se4  8  0.2380  0.0000  0.3495  1
]