data_Cu3HgS
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.82
_cell_length_b   4.82
_cell_length_c   4.82
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Cu3HgS
_chemical_formula_sum   'Cu3 Hg1 S1'
_cell_volume   112.25
_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
  Cu  Cu2  1  0.41  0.0  0.41  1.0
  Cu  Cu3  1  0.41  0.41  0.0  1.0
  Cu  Cu4  1  0.0  0.41  0.41  1.0
  Hg  Hg1  1  0.41  0.41  0.41  1.0
  S  S0  1  0.0  0.0  0.0  1.0

data_Cu3HgS
_symmetry_space_group_name_H-M   R3m
_cell_length_a   6.82
_cell_length_b   6.82
_cell_length_c   8.36
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   Cu3HgS
_chemical_formula_sum   'Cu9 Hg3 S3'
_cell_volume   336.75
_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
  Cu  Cu0  9  0.06  0.53  0.94  1.0
  Hg  Hg1  3  0.0  0.0  0.41  1.0
  S  S2  3  0.0  0.0  0.0  1.0

Cu Cu Cu Hg S
Cu Cu Cu Hg S 0 3 o o o 0 4 + o o 0 4 o o + 0 4 o o o 1 3 o o o 1 4 + o o 1 4 o + o 1 4 o o o 2 3 o o o 2 4 o + o 2 4 o o + 2 4 o o o 3 4 o o o 
Cu3HgS is Pb (Zr_0.50 Ti_0.48) O_3 structured and crystallizes in the trigonal R3m space group. Cu(1) is bonded in a 3-coordinate geometry to two equivalent Hg(1) and one S(1) atom. There is one shorter (1.99 Å) and one longer (2.84 Å) Cu(1)-Hg(1) bond length. The Cu(1)-S(1) bond length is 2.81 Å. Hg(1) is bonded to six equivalent Cu(1) atoms to form distorted corner-sharing HgCu6 octahedra. The corner-sharing octahedra are not tilted. S(1) is bonded in a 3-coordinate geometry to three equivalent Cu(1) atoms.