data_Re2NiHg
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   2.74
_cell_length_b   2.74
_cell_length_c   8.15
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Re2NiHg
_chemical_formula_sum   'Re2 Ni1 Hg1'
_cell_volume   61.16
_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
  Re  Re2  1  0.37  0.37  0.75  1.0
  Re  Re3  1  0.37  0.37  0.4  1.0
  Ni  Ni1  1  0.0  0.0  0.0  1.0
  Hg  Hg0  1  0.0  0.0  0.08  1.0

data_Re2NiHg
_symmetry_space_group_name_H-M   Cm
_cell_length_a   3.87
_cell_length_b   3.87
_cell_length_c   8.15
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   Re2NiHg
_chemical_formula_sum   'Re4 Ni2 Hg2'
_cell_volume   122.32
_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
  Re  Re0  2  0.37  0.0  0.4  1.0
  Re  Re1  2  0.37  0.0  0.75  1.0
  Ni  Ni2  2  0.0  0.0  0.0  1.0
  Hg  Hg3  2  0.0  0.0  0.08  1.0

Re Re Ni Hg
Re Re Ni Hg 0 3 o o + 0 2 o o + 0 2 o + + 0 2 + o + 0 2 + + + 0 0 + o o 0 0 o + o 0 1 o o o 1 3 o o o 1 1 + o o 1 1 o + o 2 3 o o o 
Re2NiHg crystallizes in the monoclinic Cm space group. There are two inequivalent Re sites. In the first Re site, Re(1) is bonded in a 9-coordinate geometry to one Re(2), four equivalent Re(1), and four equivalent Ni(1) atoms. The Re(1)-Re(2) bond length is 2.83 Å. All Re(1)-Re(1) bond lengths are 2.74 Å. There are a spread of Re(1)-Ni(1) bond distances ranging from 2.50-3.19 Å. In the second Re site, Re(2) is bonded in a 8-coordinate geometry to one Re(1), four equivalent Re(2), and three equivalent Hg(1) atoms. All Re(2)-Re(2) bond lengths are 2.74 Å. There is one shorter (3.02 Å) and two longer (3.33 Å) Re(2)-Hg(1) bond lengths. Ni(1) is bonded in a single-bond geometry to four equivalent Re(1) and one Hg(1) atom. The Ni(1)-Hg(1) bond length is 0.61 Å. Hg(1) is bonded in a single-bond geometry to three equivalent Re(2) and one Ni(1) atom.