data_Co3HgI
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.91
_cell_length_b   4.91
_cell_length_c   4.91
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Co3HgI
_chemical_formula_sum   'Co3 Hg1 I1'
_cell_volume   118.6
_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
  Co  Co1  1  0.46  0.0  0.46  1.0
  Co  Co2  1  0.46  0.46  0.0  1.0
  Co  Co3  1  0.0  0.46  0.46  1.0
  Hg  Hg4  1  0.46  0.46  0.46  1.0
  I  I0  1  0.0  0.0  0.0  1.0

data_Co3HgI
_symmetry_space_group_name_H-M   R3m
_cell_length_a   6.95
_cell_length_b   6.95
_cell_length_c   8.51
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   Co3HgI
_chemical_formula_sum   'Co9 Hg3 I3'
_cell_volume   355.8
_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
  Co  Co0  9  0.03  0.51  0.97  1.0
  Hg  Hg1  3  0.0  0.0  0.46  1.0
  I  I2  3  0.0  0.0  0.0  1.0

Co Co Co Hg I
Co3HgI is (Cubic) Perovskite structured and crystallizes in the trigonal R3m space group. Co(1) is bonded in a 3-coordinate geometry to two equivalent Hg(1) and three equivalent I(1) atoms. There is one shorter (2.24 Å) and one longer (2.67 Å) Co(1)-Hg(1) bond length. There is one shorter (3.17 Å) and two longer (3.49 Å) Co(1)-I(1) bond lengths. Hg(1) is bonded to six equivalent Co(1) atoms to form corner-sharing HgCo6 octahedra. The corner-sharing octahedra are not tilted. I(1) is bonded in a 9-coordinate geometry to nine equivalent Co(1) atoms.