data_Si2NiHg
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.93
_cell_length_b   5.93
_cell_length_c   5.93
_cell_angle_alpha   153.83
_cell_angle_beta   134.25
_cell_angle_gamma   53.47
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Si2NiHg
_chemical_formula_sum   'Si2 Ni1 Hg1'
_cell_volume   65.69
_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
  Si  Si2  1  0.0  0.31  0.24  1.0
  Si  Si3  1  0.34  0.0  0.06  1.0
  Ni  Ni1  1  0.0  0.0  0.0  1.0
  Hg  Hg0  1  0.0  0.0  0.3  1.0

data_Si2NiHg
_symmetry_space_group_name_H-M   P1
_cell_length_a   2.69
_cell_length_b   4.61
_cell_length_c   5.93
_cell_angle_alpha   112.88
_cell_angle_beta   103.09
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Si2NiHg
_chemical_formula_sum   'Si2 Ni1 Hg1'
_cell_volume   65.69
_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
  Si  Si0  1  0.28  0.94  0.28  1.0
  Si  Si1  1  0.76  0.07  0.07  1.0
  Ni  Ni2  1  0.0  0.0  0.0  1.0
  Hg  Hg3  1  0.7  0.7  0.7  1.0

Si Si Ni Hg
Si Si Ni Hg 0 2 o o o 0 1 o o o 1 2 o o o 2 3 o o o 