data_SiHgAu3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.17
_cell_length_b   5.17
_cell_length_c   5.17
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   SiHgAu3
_chemical_formula_sum   'Si1 Hg1 Au3'
_cell_volume   137.86
_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  Si0  1  0.0  0.0  0.0  1.0
  Hg  Hg4  1  0.58  0.58  0.58  1.0
  Au  Au1  1  0.58  0.0  0.58  1.0
  Au  Au2  1  0.58  0.58  0.0  1.0
  Au  Au3  1  0.0  0.58  0.58  1.0

data_SiHgAu3
_symmetry_space_group_name_H-M   R3m
_cell_length_a   7.31
_cell_length_b   7.31
_cell_length_c   8.95
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   SiHgAu3
_chemical_formula_sum   'Si3 Hg3 Au9'
_cell_volume   413.59
_cell_formula_units_Z   3
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  '-y, x-y, z'
  3  '-x+y, -x, z'
  4  '-y, -x, z'
  5  '-x+y, y, z'
  6  'x, x-y, z'
  7  'x+1/3, y+2/3, z+2/3'
  8  '-y+1/3, x-y+2/3, z+2/3'
  9  '-x+y+1/3, -x+2/3, z+2/3'
  10  '-y+1/3, -x+2/3, z+2/3'
  11  '-x+y+1/3, y+2/3, z+2/3'
  12  'x+1/3, x-y+2/3, z+2/3'
  13  'x+2/3, y+1/3, z+1/3'
  14  '-y+2/3, x-y+1/3, z+1/3'
  15  '-x+y+2/3, -x+1/3, z+1/3'
  16  '-y+2/3, -x+1/3, z+1/3'
  17  '-x+y+2/3, y+1/3, z+1/3'
  18  'x+2/3, x-y+1/3, z+1/3'
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  3  0.0  0.0  0.0  1.0
  Hg  Hg1  3  0.0  0.0  0.58  1.0
  Au  Au2  9  0.19  0.39  0.39  1.0

Si Hg Au Au Au
Si Hg Au Au Au 0 1 - - - 0 3 - - o 0 3 - o o 0 3 o - o 0 2 - o - 0 2 - o o 0 2 o o - 0 4 o - - 0 4 o - o 0 4 o o - 1 2 o + o 1 3 o o + 1 4 + o o 
Au3HgSi crystallizes in the trigonal R3m space group. Au(1) is bonded in a distorted single-bond geometry to two equivalent Hg(1) and one Si(1) atom. There is one shorter (2.15 Å) and one longer (3.01 Å) Au(1)-Hg(1) bond length. The Au(1)-Si(1) bond length is 3.05 Å. Hg(1) is bonded to six equivalent Au(1) atoms to form distorted corner-sharing HgAu6 octahedra. The corner-sharing octahedra are not tilted. Si(1) is bonded in a 3-coordinate geometry to three equivalent Au(1) atoms.