data_Mg2HgPb
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.74
_cell_length_b   5.74
_cell_length_c   5.11
_cell_angle_alpha   99.74
_cell_angle_beta   99.74
_cell_angle_gamma   36.19
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Mg2HgPb
_chemical_formula_sum   'Mg2 Hg1 Pb1'
_cell_volume   98.02
_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
  Mg  Mg1  1  0.99  0.0  0.82  1.0
  Mg  Mg2  1  0.96  0.0  0.38  1.0
  Hg  Hg0  1  0.04  0.0  0.04  1.0
  Pb  Pb3  1  0.02  0.0  0.34  1.0

data_Mg2HgPb
_symmetry_space_group_name_H-M   P1
_cell_length_a   3.57
_cell_length_b   5.11
_cell_length_c   5.74
_cell_angle_alpha   99.74
_cell_angle_beta   108.09
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Mg2HgPb
_chemical_formula_sum   'Mg2 Hg1 Pb1'
_cell_volume   98.02
_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
  Mg  Mg0  1  0.0  0.38  0.96  1.0
  Mg  Mg1  1  0.0  0.82  0.99  1.0
  Hg  Hg2  1  0.0  0.04  0.04  1.0
  Pb  Pb3  1  0.0  0.34  0.02  1.0

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