data_[Tl4Ag2Se4]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  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 [P4/mbm]
_cell_length_a [8.1232]
_cell_length_b [8.1232]
_cell_length_c [3.9725]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [127]
_chemical_formula_structural [Tl2AgSe2]
_chemical_formula_sum '[Tl4 Ag2 Se4]'
_cell_volume [262.1288]
_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
[
  Tl  Tl0  4  0.1471  0.3529  0.0000  1
  Ag  Ag1  2  0.0000  0.0000  0.0000  1
  Se  Se2  4  0.1596  0.6596  0.5000  1
]