data_[Na4Ag4Bi2Se8]
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
  Bi  2.0200  1.6000  1.0350
  Se  2.5500  1.1500  1.0133
]
_symmetry_space_group_name_H-M [C2/m]
_cell_length_a [15.9204]
_cell_length_b [4.1280]
_cell_length_c [7.5346]
_cell_angle_alpha [90.0000]
_cell_angle_beta [114.4233]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [12]
_chemical_formula_structural [Na2Ag2BiSe4]
_chemical_formula_sum '[Na4 Ag4 Bi2 Se8]'
_cell_volume [450.8578]
_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  0.1374  0.0000  0.5621  1.0
  Ag  Ag1  4  0.1836  0.5000  0.9791  1.0
  Bi  Bi2  2  0.0000  0.0000  0.0000  1.0
  Se  Se3  4  0.0054  0.5000  0.7201  1.0
  Se  Se4  4  0.2052  0.0000  0.2258  1.0
]