data_ZnSiHg
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.53
_cell_length_b   6.53
_cell_length_c   6.53
_cell_angle_alpha   153.19
_cell_angle_beta   153.19
_cell_angle_gamma   38.28
_symmetry_Int_Tables_number   1
_chemical_formula_structural   ZnSiHg
_chemical_formula_sum   'Zn1 Si1 Hg1'
_cell_volume   56.69
_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
  Zn  Zn2  1  0.0  0.0  0.4  1.0
  Si  Si1  1  0.0  0.0  0.9  1.0
  Hg  Hg0  1  0.0  0.0  0.04  1.0

data_ZnSiHg
_symmetry_space_group_name_H-M   Cm
_cell_length_a   4.29
_cell_length_b   4.29
_cell_length_c   6.53
_cell_angle_alpha   90.0
_cell_angle_beta   109.14
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   ZnSiHg
_chemical_formula_sum   'Zn2 Si2 Hg2'
_cell_volume   113.37
_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
  Zn  Zn0  2  0.4  0.0  0.4  1.0
  Si  Si1  2  0.4  0.5  0.9  1.0
  Hg  Hg2  2  0.04  0.0  0.04  1.0

Zn Si Hg