data_[Rb4Ac2Mg4Se8]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Rb  0.8200  2.3500  1.6600
  Ac  1.1000  1.9500  1.2600
  Mg  1.3100  1.5000  0.8600
  Se  2.5500  1.1500  1.0133
]
_symmetry_space_group_name_H-M [C2/m]
_cell_length_a [17.0019]
_cell_length_b [4.3658]
_cell_length_c [8.6413]
_cell_angle_alpha [90.0000]
_cell_angle_beta [110.8850]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [12]
_chemical_formula_structural [Rb2Ac(MgSe2)2]
_chemical_formula_sum '[Rb4 Ac2 Mg4 Se8]'
_cell_volume [599.2721]
_cell_formula_units_Z [2]
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
[
  Rb  Rb0  4  0.1243  0.0000  0.5462  1
  Ac  Ac1  2  0.0000  0.0000  0.0000  1
  Mg  Mg2  4  0.1744  0.5000  0.9764  1
  Se  Se3  4  0.0262  0.5000  0.7552  1
  Se  Se4  4  0.2061  0.0000  0.1619  1
]