data_[Ca12Cu4Si8]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Ca  1.0000  1.8000  1.1400
  Cu  1.9000  1.3500  0.8200
  Si  1.9000  1.1000  0.5400
]
_symmetry_space_group_name_H-M [Pnma]
_cell_length_a [11.8727]
_cell_length_b [4.0164]
_cell_length_c [12.2916]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [62]
_chemical_formula_structural [Ca3CuSi2]
_chemical_formula_sum '[Ca12 Cu4 Si8]'
_cell_volume [586.1360]
_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
[
  Ca  Ca0  4  0.0555  0.2500  0.6241  1
  Ca  Ca1  4  0.1172  0.7500  0.0549  1
  Ca  Ca2  4  0.2054  0.2500  0.2988  1
  Si  Si3  4  0.0316  0.7500  0.8157  1
  Cu  Cu4  4  0.1320  0.2500  0.8720  1
  Si  Si5  4  0.1973  0.7500  0.4837  1
]