data_NiHg
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.47
_cell_length_b   4.47
_cell_length_c   4.47
_cell_angle_alpha   39.33
_cell_angle_beta   39.33
_cell_angle_gamma   39.33
_symmetry_Int_Tables_number   1
_chemical_formula_structural   NiHg
_chemical_formula_sum   'Ni1 Hg1'
_cell_volume   32.24
_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
  Ni  Ni1  1  0.0  0.0  0.0  1.0
  Hg  Hg0  1  0.0  0.0  0.18  1.0

data_NiHg
_symmetry_space_group_name_H-M   Cm
_cell_length_a   5.21
_cell_length_b   3.01
_cell_length_c   4.47
_cell_angle_alpha   90.0
_cell_angle_beta   112.87
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   NiHg
_chemical_formula_sum   'Ni2 Hg2'
_cell_volume   64.49
_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
  Ni  Ni0  2  0.0  0.0  0.0  1.0
  Hg  Hg1  2  0.0  0.0  0.82  1.0

Ni Hg
Ni Hg 0 1 o o o 
HgNi is alpha carbon monoxide-like structured and crystallizes in the monoclinic Cm space group. The structure is zero-dimensional and consists of two HgNi clusters. Ni(1) is bonded in a single-bond geometry to one Hg(1) atom. The Ni(1)-Hg(1) bond length is 0.78 Å. Hg(1) is bonded in a single-bond geometry to one Ni(1) atom.