data_[Tl2Cu2Se2]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Tl  1.6200  1.9000  1.3325
  Cu  1.9000  1.3500  0.8200
  Se  2.5500  1.1500  1.0133
]
_symmetry_space_group_name_H-M [P2_1/m]
_cell_length_a [4.1431]
_cell_length_b [4.1382]
_cell_length_c [8.3185]
_cell_angle_alpha [90.0000]
_cell_angle_beta [92.3708]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [11]
_chemical_formula_structural [TlCuSe]
_chemical_formula_sum '[Tl2 Cu2 Se2]'
_cell_volume [142.4971]
_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  2  0.2498  0.2500  0.3319  1.0
  Cu  Cu1  2  0.2227  0.7500  0.9998  1.0
  Se  Se2  2  0.2582  0.2500  0.8244  1.0
]