data_FeHg2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.76
_cell_length_b   4.76
_cell_length_c   5.86
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   FeHg2
_chemical_formula_sum   'Fe2 Hg4'
_cell_volume   114.9
_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
  Fe  Fe0  1  0.38  0.37  0.39  1.0
  Fe  Fe1  1  0.0  0.75  0.46  1.0
  Hg  Hg2  1  0.0  0.0  0.93  1.0
  Hg  Hg3  1  0.0  0.0  0.0  1.0
  Hg  Hg4  1  0.0  0.75  0.39  1.0
  Hg  Hg5  1  0.38  0.37  0.46  1.0

data_FeHg2
_symmetry_space_group_name_H-M   P1
_cell_length_a   4.76
_cell_length_b   4.76
_cell_length_c   5.86
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   FeHg2
_chemical_formula_sum   'Fe2 Hg4'
_cell_volume   114.9
_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
  Fe  Fe0  1  0.0  0.75  0.46  1.0
  Fe  Fe1  1  0.38  0.37  0.39  1.0
  Hg  Hg2  1  0.0  0.0  0.0  1.0
  Hg  Hg3  1  0.0  0.0  0.93  1.0
  Hg  Hg4  1  0.0  0.75  0.39  1.0
  Hg  Hg5  1  0.38  0.37  0.46  1.0

Fe Fe Hg Hg Hg Hg
Fe Fe Hg Hg Hg Hg 0 5 o o o 1 4 o o o 2 3 o o + 
FeHgHg crystallizes in the triclinic P1 space group. The structure is zero-dimensional and consists of two FeHg clusters and one Hg cluster. In each FeHg cluster, Fe(1) is bonded in a single-bond geometry to one Hg(4) atom. The Fe(1)-Hg(4) bond length is 0.41 Å. Hg(4) is bonded in a single-bond geometry to one Fe(1) atom. In the Hg cluster, there are two inequivalent Hg sites. In the first Hg site, Hg(1) is bonded in a distorted single-bond geometry to one Hg(2) atom. The Hg(1)-Hg(2) bond length is 0.41 Å. In the second Hg site, Hg(2) is bonded in a distorted single-bond geometry to one Hg(1) atom.