data_Na2YSi
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   11.58
_cell_length_b   11.58
_cell_length_c   11.58
_cell_angle_alpha   16.38
_cell_angle_beta   16.38
_cell_angle_gamma   16.38
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Na2YSi
_chemical_formula_sum   'Na2 Y1 Si1'
_cell_volume   107.7
_cell_formula_units_Z   1
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  1  0.0  0.0  0.95  1.0
  Na  Na1  1  0.0  0.0  0.32  1.0
  Y  Y3  1  0.0  0.0  0.13  1.0
  Si  Si2  1  0.0  0.0  0.0  1.0

data_Na2YSi
_symmetry_space_group_name_H-M   Cm
_cell_length_a   5.72
_cell_length_b   3.3
_cell_length_c   11.58
_cell_angle_alpha   90.0
_cell_angle_beta   99.47
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   Na2YSi
_chemical_formula_sum   'Na4 Y2 Si2'
_cell_volume   215.4
_cell_formula_units_Z   2
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  'x, -y, z'
  3  'x+1/2, y+1/2, z'
  4  'x+1/2, -y+1/2, 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  2  0.0  0.0  0.05  1.0
  Na  Na1  2  0.0  0.0  0.68  1.0
  Y  Y2  2  0.0  0.0  0.87  1.0
  Si  Si3  2  0.0  0.0  0.0  1.0

Na Na Y Si
Na Na Y Si 0 3 o o + 1 2 o o o 2 3 o o o 