data_[Na8Er4Ge4Se16]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Na  0.9300  1.8000  1.1600
  Er  1.2400  1.7500  1.0300
  Ge  2.0100  1.2500  0.7700
  Se  2.5500  1.1500  1.0133
]
_symmetry_space_group_name_H-M [Imma]
_cell_length_a [8.0533]
_cell_length_b [8.3057]
_cell_length_c [11.6356]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [74]
_chemical_formula_structural [Na2ErGeSe4]
_chemical_formula_sum '[Na8 Er4 Ge4 Se16]'
_cell_volume [778.2853]
_cell_formula_units_Z [4]
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  0.0000  0.0000  0.5000  1
  Na  Na1  4  0.2500  0.2500  0.2500  1
  Er  Er2  4  0.0000  0.0000  0.0000  1
  Ge  Ge3  4  0.2500  0.2500  0.7500  1
  Se  Se4  8  0.0000  0.0228  0.7555  1
  Se  Se5  8  0.2411  0.2500  0.9874  1
]