data_CrSiHg3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.12
_cell_length_b   5.12
_cell_length_c   5.12
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   CrSiHg3
_chemical_formula_sum   'Cr1 Si1 Hg3'
_cell_volume   134.2
_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
  Cr  Cr0  1  0.56  0.56  0.56  1.0
  Si  Si1  1  0.0  0.0  0.0  1.0
  Hg  Hg2  1  0.0  0.56  0.0  1.0
  Hg  Hg3  1  0.0  0.0  0.56  1.0
  Hg  Hg4  1  0.56  0.0  0.0  1.0

data_CrSiHg3
_symmetry_space_group_name_H-M   R3m
_cell_length_a   7.24
_cell_length_b   7.24
_cell_length_c   8.87
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   CrSiHg3
_chemical_formula_sum   'Cr3 Si3 Hg9'
_cell_volume   402.61
_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
  Cr  Cr0  3  0.0  0.0  0.56  1.0
  Si  Si1  3  0.0  0.0  0.0  1.0
  Hg  Hg2  9  0.04  0.52  0.52  1.0

Cr Si Hg Hg Hg
Cr Si Hg Hg Hg 0 3 o o o 0 3 o + o 0 3 + o o 0 3 + + o 0 2 o o o 0 2 o o + 0 2 + o o 0 2 + o + 0 4 o o o 0 4 o o + 0 4 o + o 0 4 o + + 0 1 + + + 1 4 - o o 1 2 o - o 1 3 o o - 
CrHg3Si crystallizes in the trigonal R3m space group. Cr(1) is bonded in a 3-coordinate geometry to three equivalent Hg(1) atoms. All Cr(1)-Hg(1) bond lengths are 3.19 Å. Hg(1) is bonded in a distorted T-shaped geometry to one Cr(1) and two equivalent Si(1) atoms. There is one shorter (2.25 Å) and one longer (2.87 Å) Hg(1)-Si(1) bond length. Si(1) is bonded to six equivalent Hg(1) atoms to form corner-sharing SiHg6 octahedra. The corner-sharing octahedra are not tilted.