data_[Na4Ac4Si4O16]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Na  0.9300  1.8000  1.1600
  Ac  1.1000  1.9500  1.2600
  Si  1.9000  1.1000  0.5400
  O  3.4400  0.6000  1.2600
]
_symmetry_space_group_name_H-M [Cmcm]
_cell_length_a [5.8705]
_cell_length_b [9.3131]
_cell_length_c [7.8490]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [63]
_chemical_formula_structural [NaAcSiO4]
_chemical_formula_sum '[Na4 Ac4 Si4 O16]'
_cell_volume [429.1262]
_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
[
  Na  Na0  4  0.0000  0.1767  0.2500  1
  Ac  Ac1  4  0.0000  0.5000  0.0000  1
  Si  Si2  4  0.0000  0.1473  0.7500  1
  O  O3  8  0.0000  0.2432  0.5753  1
  O  O4  8  0.2295  0.0399  0.7500  1
]