data_Cu2HgAu
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.51
_cell_length_b   4.51
_cell_length_c   4.51
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Cu2HgAu
_chemical_formula_sum   'Cu2 Hg1 Au1'
_cell_volume   64.8
_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  Cu1  1  0.0  0.0  0.0  1.0
  Cu  Cu2  1  0.78  0.78  0.78  1.0
  Hg  Hg3  1  0.59  0.59  0.59  1.0
  Au  Au0  1  0.19  0.19  0.19  1.0

data_Cu2HgAu
_symmetry_space_group_name_H-M   R3m
_cell_length_a   4.51
_cell_length_b   4.51
_cell_length_c   11.04
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   Cu2HgAu
_chemical_formula_sum   'Cu6 Hg3 Au3'
_cell_volume   194.39
_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  3  0.0  0.0  0.0  1.0
  Cu  Cu1  3  0.0  0.0  0.22  1.0
  Hg  Hg2  3  0.0  0.0  0.41  1.0
  Au  Au3  3  0.0  0.0  0.81  1.0

Cu Cu Hg Au
Cu Cu Hg Au 0 1 - - - 0 2 - - o 0 2 - o - 0 2 o - - 0 3 o o o 1 2 o o o 1 3 o + + 1 3 + o + 1 3 + + o 2 3 o o + 2 3 o + o 2 3 + o o 
AuCu2Hg crystallizes in the trigonal R3m space group. Au(1) is bonded in a distorted single-bond geometry to one Cu(1), three equivalent Cu(2), and three equivalent Hg(1) atoms. The Au(1)-Cu(1) bond length is 2.07 Å. All Au(1)-Cu(2) bond lengths are 2.72 Å. All Au(1)-Hg(1) bond lengths are 2.72 Å. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a single-bond geometry to one Au(1), one Cu(2), and three equivalent Hg(1) atoms. The Cu(1)-Cu(2) bond length is 2.41 Å. All Cu(1)-Hg(1) bond lengths are 2.72 Å. In the second Cu site, Cu(2) is bonded in a 5-coordinate geometry to three equivalent Au(1), one Cu(1), and four equivalent Hg(1) atoms. There is one shorter (2.07 Å) and three longer (3.06 Å) Cu(2)-Hg(1) bond lengths. Hg(1) is bonded in a 10-coordinate geometry to three equivalent Au(1), three equivalent Cu(1), and four equivalent Cu(2) atoms.