data_YCdHg
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.88
_cell_length_b   4.88
_cell_length_c   4.88
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   YCdHg
_chemical_formula_sum   'Y1 Cd1 Hg1'
_cell_volume   82.09
_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
  Y  Y2  1  0.0  0.0  0.0  1.0
  Cd  Cd0  1  0.17  0.17  0.17  1.0
  Hg  Hg1  1  0.45  0.45  0.45  1.0

data_YCdHg
_symmetry_space_group_name_H-M   R3m
_cell_length_a   4.88
_cell_length_b   4.88
_cell_length_c   11.95
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   YCdHg
_chemical_formula_sum   'Y3 Cd3 Hg3'
_cell_volume   246.28
_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
  Y  Y0  3  0.0  0.0  0.0  1.0
  Cd  Cd1  3  0.0  0.0  0.83  1.0
  Hg  Hg2  3  0.0  0.0  0.55  1.0

Y Cd Hg
Y Cd Hg 0 1 o o o 0 2 o o - 0 2 o - o 0 2 - o o 1 2 o o o 1 2 o o - 1 2 o - o 1 2 - o o 
YHgCd is half-Heusler structured and crystallizes in the trigonal R3m space group. Y(1) is bonded in a distorted single-bond geometry to six equivalent Hg(1) and one Cd(1) atom. There are three shorter (3.14 Å) and three longer (3.83 Å) Y(1)-Hg(1) bond lengths. The Y(1)-Cd(1) bond length is 2.08 Å. Hg(1) is bonded in a 10-coordinate geometry to six equivalent Y(1) and four equivalent Cd(1) atoms. There are three shorter (2.90 Å) and one longer (3.29 Å) Hg(1)-Cd(1) bond length. Cd(1) is bonded in a distorted single-bond geometry to one Y(1) and four equivalent Hg(1) atoms.