data_[Na4Be4Cr2Se8]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Na  0.9300  1.8000  1.1600
  Be  1.5700  1.0500  0.5900
  Cr  1.6600  1.4000  0.9400
  Se  2.5500  1.1500  1.0133
]
_symmetry_space_group_name_H-M [C2/m]
_cell_length_a [15.1686]
_cell_length_b [3.6906]
_cell_length_c [7.1627]
_cell_angle_alpha [90.0000]
_cell_angle_beta [112.1315]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [12]
_chemical_formula_structural [Na2Be2CrSe4]
_chemical_formula_sum '[Na4 Be4 Cr2 Se8]'
_cell_volume [371.4322]
_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  0.1212  0.0000  0.5303  1.0
  Be  Be1  4  0.1781  0.5000  0.9864  1.0
  Cr  Cr2  2  0.0000  0.0000  0.0000  1.0
  Se  Se3  4  0.0257  0.5000  0.7773  1.0
  Se  Se4  4  0.2205  0.0000  0.1898  1.0
]