data_[Pm21Se3Br36]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Pm  1.1300  1.8500  1.1100
  Se  2.5500  1.1500  1.0133
  Br  2.9600  1.1500  0.8825
]
_symmetry_space_group_name_H-M [R-3]
_cell_length_a [15.1081]
_cell_length_b [15.1081]
_cell_length_c [10.0244]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [120.0000]
_symmetry_Int_Tables_number [148]
_chemical_formula_structural [Pm7SeBr12]
_chemical_formula_sum '[Pm21 Se3 Br36]'
_cell_volume [1981.5621]
_cell_formula_units_Z [3]
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  18  0.0455  0.1658  0.8395  1
  Pm  Pm1  3  0.0000  0.0000  0.5000  1
  Se  Se2  3  0.0000  0.0000  0.0000  1
  Br  Br3  18  0.0251  0.5870  0.6628  1
  Br  Br4  18  0.0508  0.1848  0.3423  1
]