data_Si2HgPb
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.31
_cell_length_b   5.31
_cell_length_c   3.32
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   106.22
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Si2HgPb
_chemical_formula_sum   'Si2 Hg1 Pb1'
_cell_volume   89.84
_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
  Si  Si2  1  0.59  0.88  0.66  1.0
  Si  Si3  1  0.59  0.12  0.66  1.0
  Hg  Hg0  1  0.0  0.0  0.0  1.0
  Pb  Pb1  1  0.19  0.0  0.0  1.0

data_Si2HgPb
_symmetry_space_group_name_H-M   P1
_cell_length_a   3.32
_cell_length_b   5.31
_cell_length_c   5.31
_cell_angle_alpha   106.22
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Si2HgPb
_chemical_formula_sum   'Si2 Hg1 Pb1'
_cell_volume   89.84
_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
  Si  Si0  1  0.66  0.59  0.12  1.0
  Si  Si1  1  0.66  0.59  0.88  1.0
  Hg  Hg2  1  0.0  0.0  0.0  1.0
  Pb  Pb3  1  -0.0  0.19  0.0  1.0

Si Si Hg Pb
Si Si Hg Pb 0 1 o + o 2 3 o o o 