data_Na3Hg
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.53
_cell_length_b   6.87
_cell_length_c   5.96
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Na3Hg
_chemical_formula_sum   'Na6 Hg2'
_cell_volume   226.28
_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  Na2  1  0.0  0.0  0.17  1.0
  Na  Na3  1  0.76  0.44  0.79  1.0
  Na  Na4  1  0.76  0.7  0.01  1.0
  Na  Na5  1  0.76  0.17  0.01  1.0
  Na  Na6  1  0.0  0.14  0.95  1.0
  Na  Na7  1  0.0  0.73  0.95  1.0
  Hg  Hg0  1  0.76  0.0  0.06  1.0
  Hg  Hg1  1  0.0  0.44  0.9  1.0

data_Na3Hg
_symmetry_space_group_name_H-M   P1
_cell_length_a   5.53
_cell_length_b   5.96
_cell_length_c   6.87
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Na3Hg
_chemical_formula_sum   'Na6 Hg2'
_cell_volume   226.28
_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  0.83  0.0  1.0
  Na  Na1  1  0.0  0.05  0.27  1.0
  Na  Na2  1  0.0  0.05  0.86  1.0
  Na  Na3  1  0.24  0.21  0.56  1.0
  Na  Na4  1  0.24  0.99  0.3  1.0
  Na  Na5  1  0.24  0.99  0.83  1.0
  Hg  Hg6  1  0.0  0.1  0.56  1.0
  Hg  Hg7  1  0.24  0.94  0.0  1.0

Na Na Na Na Na Na Hg Hg
Na Na Na Na Na Na Hg Hg 0 6 - o o 0 4 o o - 1 7 + o o 2 5 + o - 3 4 + o - 3 6 o o o 