data_[Pm8Tm8Se20]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Pm  1.1300  1.8500  1.1100
  Tm  1.2500  1.7500  1.0950
  Se  2.5500  1.1500  1.0133
]
_symmetry_space_group_name_H-M [Ima2]
_cell_length_a [17.8685]
_cell_length_b [8.2069]
_cell_length_c [7.0902]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [46]
_chemical_formula_structural [Pm2Tm2Se5]
_chemical_formula_sum '[Pm8 Tm8 Se20]'
_cell_volume [1039.7365]
_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
[
  Pm  Pm0  8  0.0933  0.0690  0.5135  1
  Tm  Tm1  4  0.0000  0.0000  0.9776  1
  Tm  Tm2  4  0.2500  0.6032  0.5415  1
  Se  Se3  8  0.0321  0.7104  0.7754  1
  Se  Se4  8  0.1465  0.1048  0.9065  1
  Se  Se5  4  0.2500  0.5770  0.9261  1
]