data_[Ac2Er2Se4]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Ac  1.1000  1.9500  1.2600
  Er  1.2400  1.7500  1.0300
  Se  2.5500  1.1500  1.0133
]
_symmetry_space_group_name_H-M [Pmn2_1]
_cell_length_a [4.4241]
_cell_length_b [9.5018]
_cell_length_c [6.8144]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [31]
_chemical_formula_structural [AcErSe2]
_chemical_formula_sum '[Ac2 Er2 Se4]'
_cell_volume [286.4607]
_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
[
  Ac  Ac0  2  0.0000  0.9061  0.9284  1
  Er  Er1  2  0.0000  0.3507  0.8010  1
  Se  Se2  2  0.0000  0.1881  0.1328  1
  Se  Se3  2  0.0000  0.5836  0.0711  1
]