data_Sr2FeHg
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.09
_cell_length_b   9.09
_cell_length_c   9.09
_cell_angle_alpha   26.04
_cell_angle_beta   26.04
_cell_angle_gamma   26.04
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Sr2FeHg
_chemical_formula_sum   'Sr2 Fe1 Hg1'
_cell_volume   127.46
_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
  Sr  Sr2  1  0.0  0.0  0.47  1.0
  Sr  Sr3  1  0.0  0.0  0.86  1.0
  Fe  Fe0  1  0.0  0.0  0.0  1.0
  Hg  Hg1  1  0.0  0.0  0.16  1.0

data_Sr2FeHg
_symmetry_space_group_name_H-M   Cm
_cell_length_a   7.09
_cell_length_b   4.1
_cell_length_c   9.09
_cell_angle_alpha   90.0
_cell_angle_beta   105.08
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   Sr2FeHg
_chemical_formula_sum   'Sr4 Fe2 Hg2'
_cell_volume   254.92
_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
  Sr  Sr0  2  0.0  0.0  0.14  1.0
  Sr  Sr1  2  0.0  0.0  0.53  1.0
  Fe  Fe2  2  0.0  0.0  0.0  1.0
  Hg  Hg3  2  0.0  0.0  0.84  1.0

Sr Sr Fe Hg
Sr Sr Fe Hg 0 3 o o o 1 2 o o + 2 3 o o o 