data_HfSn2Hg
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.18
_cell_length_b   5.18
_cell_length_c   5.18
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   HfSn2Hg
_chemical_formula_sum   'Hf1 Sn2 Hg1'
_cell_volume   98.42
_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
  Hf  Hf0  1  0.66  0.66  0.66  1.0
  Sn  Sn2  1  0.0  0.0  0.0  1.0
  Sn  Sn3  1  0.83  0.83  0.83  1.0
  Hg  Hg1  1  0.5  0.5  0.5  1.0

data_HfSn2Hg
_symmetry_space_group_name_H-M   R3m
_cell_length_a   5.18
_cell_length_b   5.18
_cell_length_c   12.69
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   HfSn2Hg
_chemical_formula_sum   'Hf3 Sn6 Hg3'
_cell_volume   295.25
_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
  Hf  Hf0  3  0.0  0.0  0.34  1.0
  Sn  Sn1  3  0.0  0.0  0.0  1.0
  Sn  Sn2  3  0.0  0.0  0.17  1.0
  Hg  Hg3  3  0.0  0.0  0.5  1.0

Hf Sn Sn Hg
HfHgSn2 crystallizes in the trigonal R3m space group. Hf(1) is bonded in a distorted linear geometry to one Hg(1), one Sn(2), and three equivalent Sn(1) atoms. The Hf(1)-Hg(1) bond length is 2.13 Å. The Hf(1)-Sn(2) bond length is 2.13 Å. All Hf(1)-Sn(1) bond lengths are 2.99 Å. Hg(1) is bonded in a single-bond geometry to one Hf(1) atom. There are two inequivalent Sn sites. In the first Sn site, Sn(1) is bonded to three equivalent Hf(1) and one Sn(2) atom to form corner-sharing SnHf3Sn trigonal pyramids. The Sn(1)-Sn(2) bond length is 2.13 Å. In the second Sn site, Sn(2) is bonded in a distorted single-bond geometry to one Hf(1) and one Sn(1) atom.