data_[Na2Cu2Se3]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Na  0.9300  1.8000  1.1600
  Cu  1.9000  1.3500  0.8200
  Se  2.5500  1.1500  1.0133
]
_symmetry_space_group_name_H-M [P-1]
_cell_length_a [3.7329]
_cell_length_b [5.6973]
_cell_length_c [8.4596]
_cell_angle_alpha [90.6676]
_cell_angle_beta [90.6839]
_cell_angle_gamma [109.0374]
_symmetry_Int_Tables_number [2]
_chemical_formula_structural [Na2Cu2Se3]
_chemical_formula_sum '[Na2 Cu2 Se3]'
_cell_volume [170.0372]
_cell_formula_units_Z [1]
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  2  0.1150  0.2491  0.6751  1.0
  Cu  Cu1  2  0.4021  0.8133  0.8355  1.0
  Se  Se2  2  0.1673  0.3170  0.3238  1.0
  Se  Se3  1  0.0000  0.0000  0.0000  1.0
]