data_[Sm4Sn4Pb8Se20]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Sm  1.1700  1.8500  1.2290
  Sn  1.9600  1.4500  0.8300
  Pb  2.3300  1.8000  1.1225
  Se  2.5500  1.1500  1.0133
]
_symmetry_space_group_name_H-M [Cmc2_1]
_cell_length_a [4.3014]
_cell_length_b [18.5728]
_cell_length_c [13.3398]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [36]
_chemical_formula_structural [SmSnPb2Se5]
_chemical_formula_sum '[Sm4 Sn4 Pb8 Se20]'
_cell_volume [1065.6917]
_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
[
  Sm  Sm0  4  0.0000  0.2130  0.0172  1
  Sn  Sn1  4  0.0000  0.4588  0.4490  1
  Pb  Pb2  4  0.0000  0.1238  0.6666  1
  Pb  Pb3  4  0.0000  0.1278  0.2963  1
  Se  Se4  4  0.0000  0.0538  0.0749  1
  Se  Se5  4  0.0000  0.2817  0.6684  1
  Se  Se6  4  0.0000  0.3205  0.3733  1
  Se  Se7  4  0.0000  0.3682  0.0132  1
  Se  Se8  4  0.0000  0.4828  0.7650  1
]