data_[Na8Sm4Al4Se16]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Na  0.9300  1.8000  1.1600
  Sm  1.1700  1.8500  1.2290
  Al  1.6100  1.2500  0.6750
  Se  2.5500  1.1500  1.0133
]
_symmetry_space_group_name_H-M [Imma]
_cell_length_a [7.9182]
_cell_length_b [8.4546]
_cell_length_c [11.6507]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [74]
_chemical_formula_structural [Na2SmAlSe4]
_chemical_formula_sum '[Na8 Sm4 Al4 Se16]'
_cell_volume [779.9672]
_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
  Sm  Sm2  4  0.0000  0.0000  0.0000  1
  Al  Al3  4  0.2500  0.2500  0.7500  1
  Se  Se4  8  0.0000  0.0407  0.7493  1
  Se  Se5  8  0.2497  0.2500  0.9844  1
]