data_[Nb2Tl4Ag2Se8]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Nb  1.6000  1.4500  0.8200
  Tl  1.6200  1.9000  1.3325
  Ag  1.9300  1.6000  1.0867
  Se  2.5500  1.1500  1.0133
]
_symmetry_space_group_name_H-M [I-4]
_cell_length_a [7.8955]
_cell_length_b [7.8955]
_cell_length_c [8.1669]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [82]
_chemical_formula_structural [NbTl2AgSe4]
_chemical_formula_sum '[Nb2 Tl4 Ag2 Se8]'
_cell_volume [509.1165]
_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
[
  Nb  Nb0  2  0.0000  0.0000  0.5000  1.0
  Tl  Tl1  2  0.0000  0.0000  0.0000  1.0
  Tl  Tl2  2  0.0000  0.5000  0.2500  1.0
  Ag  Ag3  2  0.0000  0.5000  0.7500  1.0
  Se  Se4  8  0.1508  0.2025  0.6707  1.0
]