data_NaSi
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.6
_cell_length_b   4.6
_cell_length_c   5.28
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   NaSi
_chemical_formula_sum   'Na2 Si2'
_cell_volume   96.61
_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
  Na  Na0  1  0.0  0.0  0.64  1.0
  Na  Na1  1  0.0  0.0  0.0  1.0
  Si  Si2  1  0.3  0.33  0.96  1.0
  Si  Si3  1  0.0  0.65  0.32  1.0

data_NaSi
_symmetry_space_group_name_H-M   P1
_cell_length_a   4.6
_cell_length_b   4.6
_cell_length_c   5.28
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   NaSi
_chemical_formula_sum   'Na2 Si2'
_cell_volume   96.61
_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
  Na  Na0  1  0.0  0.0  0.0  1.0
  Na  Na1  1  0.0  0.0  0.64  1.0
  Si  Si2  1  0.0  0.65  0.32  1.0
  Si  Si3  1  0.3  0.33  0.96  1.0

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