data_[Na4Si2Ge2Se8]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Na  0.9300  1.8000  1.1600
  Si  1.9000  1.1000  0.5400
  Ge  2.0100  1.2500  0.7700
  Se  2.5500  1.1500  1.0133
]
_symmetry_space_group_name_H-M [Pmn2_1]
_cell_length_a [9.5786]
_cell_length_b [7.7860]
_cell_length_c [6.1988]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [31]
_chemical_formula_structural [Na2SiGeSe4]
_chemical_formula_sum '[Na4 Si2 Ge2 Se8]'
_cell_volume [462.2949]
_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  0.2488  0.3270  0.4493  1.0
  Si  Si1  2  0.0000  0.1536  0.0073  1.0
  Ge  Ge2  2  0.0000  0.8142  0.4750  1.0
  Se  Se3  4  0.2034  0.2951  0.9275  1.0
  Se  Se4  2  0.0000  0.1240  0.3820  1.0
  Se  Se5  2  0.0000  0.8707  0.8821  1.0
]