data_[Sm3U6O21]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Sm  1.1700  1.8500  1.2290
  U  1.3800  1.7500  0.9913
  O  3.4400  0.6000  1.2600
]
_symmetry_space_group_name_H-M [R-3m]
_cell_length_a [3.8492]
_cell_length_b [3.8492]
_cell_length_c [31.0313]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [120.0000]
_symmetry_Int_Tables_number [166]
_chemical_formula_structural [SmU2O7]
_chemical_formula_sum '[Sm3 U6 O21]'
_cell_volume [398.1770]
_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
[
  Sm  Sm0  3  -0.0000  -0.0000  0.5000  1
  U  U1  6  0.0000  0.0000  0.9331  1
  O  O2  6  0.0000  0.0000  0.1365  1
  O  O3  6  0.0000  0.0000  0.2801  1
  O  O4  6  0.0000  0.0000  0.4214  1
  O  O5  3  0.0000  0.0000  0.0000  1
]