data_[Ca4Ac2Si4]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Ca  1.0000  1.8000  1.1400
  Ac  1.1000  1.9500  1.2600
  Si  1.9000  1.1000  0.5400
]
_symmetry_space_group_name_H-M [P2_1/m]
_cell_length_a [5.3433]
_cell_length_b [4.5457]
_cell_length_c [11.9734]
_cell_angle_alpha [90.0000]
_cell_angle_beta [94.4002]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [11]
_chemical_formula_structural [Ca2AcSi2]
_chemical_formula_sum '[Ca4 Ac2 Si4]'
_cell_volume [289.9658]
_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
[
  Ca  Ca0  2  0.1288  0.2500  0.1070  1
  Ca  Ca1  2  0.2459  0.7500  0.5046  1
  Ac  Ac2  2  0.3590  0.2500  0.7650  1
  Si  Si3  2  0.2359  0.2500  0.3487  1
  Si  Si4  2  0.3893  0.7500  0.9836  1
]