data_SiHg2Te
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.3
_cell_length_b   3.3
_cell_length_c   9.02
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   SiHg2Te
_chemical_formula_sum   'Si1 Hg2 Te1'
_cell_volume   98.26
_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
  Si  Si2  1  0.0  0.0  0.0  1.0
  Hg  Hg0  1  0.65  0.65  0.18  1.0
  Hg  Hg1  1  0.65  0.65  0.84  1.0
  Te  Te3  1  0.0  0.0  0.51  1.0

data_SiHg2Te
_symmetry_space_group_name_H-M   Cm
_cell_length_a   4.67
_cell_length_b   4.67
_cell_length_c   9.02
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   SiHg2Te
_chemical_formula_sum   'Si2 Hg4 Te2'
_cell_volume   196.52
_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
  Si  Si0  2  0.0  0.0  0.0  1.0
  Hg  Hg1  2  0.15  0.5  0.18  1.0
  Hg  Hg2  2  0.15  0.5  0.84  1.0
  Te  Te3  2  0.0  0.0  0.51  1.0

Si Hg Hg Te
Si Hg Hg Te 0 2 - - - 0 1 - - o 1 3 + + o 1 3 + o o 1 3 o + o 2 3 + + o 2 3 + o o 2 3 o + o 3 3 + o o 3 3 o + o 
Hg2SiTe crystallizes in the monoclinic Cm space group. There are two inequivalent Hg sites. In the first Hg site, Hg(1) is bonded in a distorted single-bond geometry to three equivalent Si(1) and one Te(1) atom. There is one shorter (2.28 Å) and two longer (2.91 Å) Hg(1)-Si(1) bond lengths. The Hg(1)-Te(1) bond length is 3.42 Å. In the second Hg site, Hg(2) is bonded in a distorted single-bond geometry to three equivalent Si(1) and one Te(1) atom. There is one shorter (2.17 Å) and two longer (2.82 Å) Hg(2)-Si(1) bond lengths. The Hg(2)-Te(1) bond length is 3.42 Å. Si(1) is bonded in a 6-coordinate geometry to three equivalent Hg(1) and three equivalent Hg(2) atoms. Te(1) is bonded to one Hg(1), one Hg(2), and four equivalent Te(1) atoms to form a mixture of distorted corner and edge-sharing TeHg2Te4 octahedra. The corner-sharing octahedra are not tilted. All Te(1)-Te(1) bond lengths are 3.30 Å.