data_HgRu
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   2.9
_cell_length_b   2.9
_cell_length_c   8.52
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   HgRu
_chemical_formula_sum   'Hg2 Ru2'
_cell_volume   71.54
_cell_formula_units_Z   2
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
  Hg  Hg0  1  0.45  0.0  0.58  1.0
  Hg  Hg1  1  0.0  0.45  0.94  1.0
  Ru  Ru2  1  0.45  0.0  0.79  1.0
  Ru  Ru3  1  0.0  0.45  0.73  1.0

data_HgRu
_symmetry_space_group_name_H-M   C2/m
_cell_length_a   4.1
_cell_length_b   4.1
_cell_length_c   8.52
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   12
_chemical_formula_structural   HgRu
_chemical_formula_sum   'Hg4 Ru4'
_cell_volume   143.08
_cell_formula_units_Z   4
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  '-x, -y, -z'
  3  '-x, y, -z'
  4  'x, -y, z'
  5  'x+1/2, y+1/2, z'
  6  '-x+1/2, -y+1/2, -z'
  7  '-x+1/2, y+1/2, -z'
  8  '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
  Hg  Hg0  4  0.22  0.5  0.32  1.0
  Ru  Ru1  4  0.22  0.5  0.53  1.0

Hg Hg Ru Ru
Hg Hg Ru Ru 0 2 o o o 0 3 o o o 1 3 o o o 1 2 o o o 2 3 o - o 2 3 o o o 2 3 + - o 2 3 + o o 
RuHg crystallizes in the monoclinic C2/m space group. The structure is zero-dimensional and consists of four RuHg clusters. Ru(1) is bonded in a distorted single-bond geometry to one Hg(1) atom. The Ru(1)-Hg(1) bond length is 1.77 Å. Hg(1) is bonded in a distorted single-bond geometry to one Ru(1) atom.