data_Mg2HgRu
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.39
_cell_length_b   3.39
_cell_length_c   6.18
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Mg2HgRu
_chemical_formula_sum   'Mg2 Hg1 Ru1'
_cell_volume   71.12
_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  Mg1  1  0.7  0.7  0.83  1.0
  Mg  Mg2  1  0.7  0.7  0.35  1.0
  Hg  Hg0  1  0.0  0.0  0.09  1.0
  Ru  Ru3  1  0.0  0.0  0.0  1.0

data_Mg2HgRu
_symmetry_space_group_name_H-M   Cm
_cell_length_a   4.8
_cell_length_b   4.8
_cell_length_c   6.18
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   Mg2HgRu
_chemical_formula_sum   'Mg4 Hg2 Ru2'
_cell_volume   142.25
_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  0.2  0.5  0.35  1.0
  Mg  Mg1  2  0.2  0.5  0.83  1.0
  Hg  Hg2  2  0.0  0.0  0.09  1.0
  Ru  Ru3  2  0.0  0.0  0.0  1.0

Mg Mg Hg Ru
Mg Mg Hg Ru 0 3 + + + 0 2 + + + 1 3 + + o 1 2 + + o 2 3 o o o 
Mg2RuHg crystallizes in the monoclinic Cm space group. The structure is zero-dimensional and consists of two Mg2RuHg clusters. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a distorted single-bond geometry to one Ru(1) atom. The Mg(1)-Ru(1) bond length is 1.81 Å. In the second Mg site, Mg(2) is bonded in a distorted single-bond geometry to one Hg(1) atom. The Mg(2)-Hg(1) bond length is 2.18 Å. Ru(1) is bonded in a 2-coordinate geometry to one Mg(1) and one Hg(1) atom. The Ru(1)-Hg(1) bond length is 0.55 Å. Hg(1) is bonded in a distorted single-bond geometry to one Mg(2) and one Ru(1) atom.