data_[Ac8Tb4Mg4Se20]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Ac  1.1000  1.9500  1.2600
  Tb  1.1000  1.7500  0.9815
  Mg  1.3100  1.5000  0.8600
  Se  2.5500  1.1500  1.0133
]
_symmetry_space_group_name_H-M [Cmc2_1]
_cell_length_a [4.2538]
_cell_length_b [18.0430]
_cell_length_c [12.9367]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [36]
_chemical_formula_structural [Ac2TbMgSe5]
_chemical_formula_sum '[Ac8 Tb4 Mg4 Se20]'
_cell_volume [992.9068]
_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
[
  Ac  Ac0  4  0.0000  0.1135  0.6868  1
  Ac  Ac1  4  0.0000  0.1350  0.3094  1
  Tb  Tb2  4  0.0000  0.2032  0.0134  1
  Mg  Mg3  4  0.0000  0.4565  0.4539  1
  Se  Se4  4  0.0000  0.0476  0.0605  1
  Se  Se5  4  0.0000  0.2874  0.6656  1
  Se  Se6  4  0.0000  0.3154  0.3603  1
  Se  Se7  4  0.0000  0.3618  0.0015  1
  Se  Se8  4  0.0000  0.4935  0.7726  1
]