data_TiSi2Hg
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.08
_cell_length_b   5.08
_cell_length_c   5.08
_cell_angle_alpha   134.12
_cell_angle_beta   134.12
_cell_angle_gamma   66.91
_symmetry_Int_Tables_number   1
_chemical_formula_structural   TiSi2Hg
_chemical_formula_sum   'Ti1 Si2 Hg1'
_cell_volume   66.4
_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
  Ti  Ti3  1  0.0  0.0  0.0  1.0
  Si  Si1  1  0.98  0.0  0.12  1.0
  Si  Si2  1  0.0  0.98  0.12  1.0
  Hg  Hg0  1  0.0  0.0  0.24  1.0

data_TiSi2Hg
_symmetry_space_group_name_H-M   Cm
_cell_length_a   5.6
_cell_length_b   5.6
_cell_length_c   5.08
_cell_angle_alpha   90.0
_cell_angle_beta   123.45
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   TiSi2Hg
_chemical_formula_sum   'Ti2 Si4 Hg2'
_cell_volume   132.79
_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
  Ti  Ti0  2  0.0  0.0  0.0  1.0
  Si  Si1  4  0.01  0.01  0.14  1.0
  Hg  Hg2  2  0.0  0.0  0.24  1.0

Ti Si Si Hg
Ti Si Si Hg 0 1 - o o 0 2 o - o 1 2 + - o 1 3 + o o 2 3 o + o 
TiHgSi2 crystallizes in the monoclinic Cm space group. The structure is zero-dimensional and consists of two TiHgSi2 clusters. Ti(1) is bonded in a 2-coordinate geometry to two equivalent Si(1) atoms. Both Ti(1)-Si(1) bond lengths are 0.68 Å. Hg(1) is bonded in a 2-coordinate geometry to two equivalent Si(1) atoms. Both Hg(1)-Si(1) bond lengths are 0.53 Å. Si(1) is bonded in a single-bond geometry to one Ti(1), one Hg(1), and one Si(1) atom. The Si(1)-Si(1) bond length is 0.12 Å.