data_NiHgSe2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.05
_cell_length_b   5.05
_cell_length_c   6.25
_cell_angle_alpha   102.62
_cell_angle_beta   102.62
_cell_angle_gamma   40.53
_symmetry_Int_Tables_number   1
_chemical_formula_structural   NiHgSe2
_chemical_formula_sum   'Ni1 Hg1 Se2'
_cell_volume   100.61
_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  0.01  0.0  0.04  1.0
  Se  Se2  1  0.75  0.0  0.17  1.0
  Se  Se3  1  0.27  0.0  0.9  1.0

data_NiHgSe2
_symmetry_space_group_name_H-M   P1
_cell_length_a   3.5
_cell_length_b   5.05
_cell_length_c   6.25
_cell_angle_alpha   102.62
_cell_angle_beta   90.0
_cell_angle_gamma   110.27
_symmetry_Int_Tables_number   1
_chemical_formula_structural   NiHgSe2
_chemical_formula_sum   'Ni1 Hg1 Se2'
_cell_volume   100.61
_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  Ni0  1  0.0  0.0  0.0  1.0
  Hg  Hg1  1  0.0  0.99  0.96  1.0
  Se  Se2  1  0.0  0.25  0.83  1.0
  Se  Se3  1  0.0  0.73  0.1  1.0

Ni Hg Se Se
Ni Hg Se Se 0 1 o o o 0 2 - o o 0 3 o o - 1 2 - o o 1 3 o o - 
NiHgSe2 is Indium-like structured and crystallizes in the triclinic P1 space group. The structure is zero-dimensional and consists of one NiHgSe2 cluster. Ni(1) is bonded in a single-bond geometry to one Hg(1) and one Se(2) atom. The Ni(1)-Hg(1) bond length is 0.23 Å. The Ni(1)-Se(2) bond length is 1.59 Å. Hg(1) is bonded in a single-bond geometry to one Ni(1) and one Se(1) atom. The Hg(1)-Se(1) bond length is 1.70 Å. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded in a single-bond geometry to one Hg(1) atom. In the second Se site, Se(2) is bonded in a single-bond geometry to one Ni(1) atom.