data_Ni2HgCl
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.52
_cell_length_b   4.52
_cell_length_c   4.52
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Ni2HgCl
_chemical_formula_sum   'Ni2 Hg1 Cl1'
_cell_volume   65.26
_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  Ni2  1  0.2  0.2  0.2  1.0
  Ni  Ni3  1  0.6  0.6  0.6  1.0
  Hg  Hg1  1  0.79  0.79  0.79  1.0
  Cl  Cl0  1  0.0  0.0  0.0  1.0

data_Ni2HgCl
_symmetry_space_group_name_H-M   R3m
_cell_length_a   4.52
_cell_length_b   4.52
_cell_length_c   11.07
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   Ni2HgCl
_chemical_formula_sum   'Ni6 Hg3 Cl3'
_cell_volume   195.79
_cell_formula_units_Z   3
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  '-y, x-y, z'
  3  '-x+y, -x, z'
  4  '-y, -x, z'
  5  '-x+y, y, z'
  6  'x, x-y, z'
  7  'x+1/3, y+2/3, z+2/3'
  8  '-y+1/3, x-y+2/3, z+2/3'
  9  '-x+y+1/3, -x+2/3, z+2/3'
  10  '-y+1/3, -x+2/3, z+2/3'
  11  '-x+y+1/3, y+2/3, z+2/3'
  12  'x+1/3, x-y+2/3, z+2/3'
  13  'x+2/3, y+1/3, z+1/3'
  14  '-y+2/3, x-y+1/3, z+1/3'
  15  '-x+y+2/3, -x+1/3, z+1/3'
  16  '-y+2/3, -x+1/3, z+1/3'
  17  '-x+y+2/3, y+1/3, z+1/3'
  18  'x+2/3, x-y+1/3, z+1/3'
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  3  0.0  0.0  0.4  1.0
  Ni  Ni1  3  0.0  0.0  0.8  1.0
  Hg  Hg2  3  0.0  0.0  0.21  1.0
  Cl  Cl3  3  0.0  0.0  -0.0  1.0

Ni Ni Hg Cl
Ni Ni Hg Cl 0 3 o o o 0 3 o o + 0 3 + o o 0 3 o + o 0 2 - - o 0 2 - o - 0 2 o - - 0 1 - o o 0 1 o - o 0 1 o o - 1 2 o - o 1 2 - o o 1 2 o o - 1 2 o o o 1 3 o + + 1 3 + o + 1 3 + + o 2 3 + + + 
Ni2HgCl crystallizes in the trigonal R3m space group. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded in a single-bond geometry to one Cl(1) atom. The Ni(1)-Cl(1) bond length is 2.16 Å. In the second Ni site, Ni(2) is bonded in a 4-coordinate geometry to one Hg(1) and three equivalent Cl(1) atoms. The Ni(2)-Hg(1) bond length is 2.16 Å. All Ni(2)-Cl(1) bond lengths are 2.72 Å. Hg(1) is bonded in a 2-coordinate geometry to one Ni(2) and one Cl(1) atom. The Hg(1)-Cl(1) bond length is 2.29 Å. Cl(1) is bonded in a 2-coordinate geometry to one Ni(1), three equivalent Ni(2), and one Hg(1) atom.