data_[Na4Sr2Cu4Se8]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Na  0.9300  1.8000  1.1600
  Sr  0.9500  2.0000  1.3200
  Cu  1.9000  1.3500  0.8200
  Se  2.5500  1.1500  1.0133
]
_symmetry_space_group_name_H-M [C2/m]
_cell_length_a [16.6232]
_cell_length_b [4.2331]
_cell_length_c [6.4547]
_cell_angle_alpha [90.0000]
_cell_angle_beta [105.8844]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [12]
_chemical_formula_structural [Na2Sr(CuSe2)2]
_chemical_formula_sum '[Na4 Sr2 Cu4 Se8]'
_cell_volume [436.8617]
_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  0.1591  0.0000  0.6082  1.0
  Sr  Sr1  2  0.0000  0.0000  0.0000  1.0
  Cu  Cu2  4  0.1900  0.5000  0.9887  1.0
  Se  Se3  4  0.0483  0.5000  0.6998  1.0
  Se  Se4  4  0.1908  0.0000  0.1844  1.0
]