data_MgHgCl
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.83
_cell_length_b   6.83
_cell_length_c   6.83
_cell_angle_alpha   151.58
_cell_angle_beta   151.58
_cell_angle_gamma   40.63
_symmetry_Int_Tables_number   1
_chemical_formula_structural   MgHgCl
_chemical_formula_sum   'Mg1 Hg1 Cl1'
_cell_volume   72.12
_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  0.0  0.0  0.45  1.0
  Hg  Hg1  1  0.0  0.0  0.95  1.0
  Cl  Cl0  1  0.0  0.0  0.24  1.0

data_MgHgCl
_symmetry_space_group_name_H-M   Cm
_cell_length_a   4.74
_cell_length_b   4.74
_cell_length_c   6.83
_cell_angle_alpha   90.0
_cell_angle_beta   110.32
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   MgHgCl
_chemical_formula_sum   'Mg2 Hg2 Cl2'
_cell_volume   144.25
_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  0.0  0.0  0.55  1.0
  Hg  Hg1  2  0.0  0.0  0.05  1.0
  Cl  Cl2  2  0.0  0.0  0.76  1.0

Mg Hg Cl
Mg Hg Cl 0 2 o o o 1 2 o o + 
MgHgCl crystallizes in the monoclinic Cm space group. The structure is zero-dimensional and consists of two MgHgCl clusters. Mg(1) is bonded in a single-bond geometry to one Cl(1) atom. The Mg(1)-Cl(1) bond length is 1.43 Å. Hg(1) is bonded in a single-bond geometry to one Cl(1) atom. The Hg(1)-Cl(1) bond length is 2.00 Å. Cl(1) is bonded in a linear geometry to one Mg(1) and one Hg(1) atom.