data_Mg2CrHg
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   2.89
_cell_length_b   2.89
_cell_length_c   8.85
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Mg2CrHg
_chemical_formula_sum   'Mg2 Cr1 Hg1'
_cell_volume   73.73
_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  Mg2  1  0.44  0.44  0.87  1.0
  Mg  Mg3  1  0.44  0.44  0.98  1.0
  Cr  Cr0  1  0.0  0.0  0.0  1.0
  Hg  Hg1  1  0.0  0.0  0.42  1.0

data_Mg2CrHg
_symmetry_space_group_name_H-M   Cm
_cell_length_a   4.08
_cell_length_b   4.08
_cell_length_c   8.85
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   Mg2CrHg
_chemical_formula_sum   'Mg4 Cr2 Hg2'
_cell_volume   147.47
_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
  Mg  Mg0  2  0.44  0.0  0.87  1.0
  Mg  Mg1  2  0.44  0.0  0.98  1.0
  Cr  Cr2  2  0.0  0.0  0.0  1.0
  Hg  Hg3  2  0.0  0.0  0.42  1.0

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