data_TlHgBr2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.75
_cell_length_b   5.75
_cell_length_c   5.75
_cell_angle_alpha   129.86
_cell_angle_beta   112.71
_cell_angle_gamma   88.45
_symmetry_Int_Tables_number   1
_chemical_formula_structural   TlHgBr2
_chemical_formula_sum   'Tl1 Hg1 Br2'
_cell_volume   127.76
_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
  Tl  Tl3  1  0.0  0.0  0.12  1.0
  Hg  Hg2  1  0.0  0.0  0.0  1.0
  Br  Br0  1  0.44  0.0  0.84  1.0
  Br  Br1  1  0.0  0.18  0.28  1.0

data_TlHgBr2
_symmetry_space_group_name_H-M   P1
_cell_length_a   4.87
_cell_length_b   5.75
_cell_length_c   5.75
_cell_angle_alpha   67.29
_cell_angle_beta   64.93
_cell_angle_gamma   64.93
_symmetry_Int_Tables_number   1
_chemical_formula_structural   TlHgBr2
_chemical_formula_sum   'Tl1 Hg1 Br2'
_cell_volume   127.76
_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
  Tl  Tl0  1  0.12  -0.0  0.88  1.0
  Hg  Hg1  1  0.0  0.0  0.0  1.0
  Br  Br2  1  0.28  -0.0  0.9  1.0
  Br  Br3  1  0.4  0.44  0.16  1.0

Tl Hg Br Br
HgTlBr2 is Indium-like structured and crystallizes in the triclinic P1 space group. The structure is zero-dimensional and consists of one HgTlBr2 cluster. Hg(1) is bonded in a single-bond geometry to one Tl(1) and one Br(1) atom. The Hg(1)-Tl(1) bond length is 0.68 Å. The Hg(1)-Br(1) bond length is 2.99 Å. Tl(1) is bonded in a water-like geometry to one Hg(1) and one Br(2) atom. The Tl(1)-Br(2) bond length is 0.85 Å. There are two inequivalent Br sites. In the first Br site, Br(1) is bonded in a distorted single-bond geometry to one Hg(1) atom. In the second Br site, Br(2) is bonded in a single-bond geometry to one Tl(1) atom.