data_Si2HgTe
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.93
_cell_length_b   4.93
_cell_length_c   4.93
_cell_angle_alpha   117.82
_cell_angle_beta   117.82
_cell_angle_gamma   93.82
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Si2HgTe
_chemical_formula_sum   'Si2 Hg1 Te1'
_cell_volume   87.3
_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  Si1  1  0.0  0.55  0.68  1.0
  Si  Si2  1  0.55  0.0  0.68  1.0
  Hg  Hg0  1  0.0  0.0  0.37  1.0
  Te  Te3  1  0.0  0.0  0.0  1.0

data_Si2HgTe
_symmetry_space_group_name_H-M   Cm
_cell_length_a   6.74
_cell_length_b   7.2
_cell_length_c   4.93
_cell_angle_alpha   90.0
_cell_angle_beta   133.09
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   Si2HgTe
_chemical_formula_sum   'Si4 Hg2 Te2'
_cell_volume   174.6
_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
  Si  Si0  4  0.09  0.23  0.32  1.0
  Hg  Hg1  2  0.13  0.5  0.63  1.0
  Te  Te2  2  0.0  0.0  0.0  1.0

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