data_Hf2AlHg
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.07
_cell_length_b   10.07
_cell_length_c   10.07
_cell_angle_alpha   17.81
_cell_angle_beta   17.81
_cell_angle_gamma   17.81
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Hf2AlHg
_chemical_formula_sum   'Hf2 Al1 Hg1'
_cell_volume   83.32
_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  Hf1  1  0.0  0.0  0.49  1.0
  Hf  Hf2  1  0.0  0.0  0.22  1.0
  Al  Al0  1  0.0  0.0  0.0  1.0
  Hg  Hg3  1  0.0  0.0  0.86  1.0

data_Hf2AlHg
_symmetry_space_group_name_H-M   Cm
_cell_length_a   5.4
_cell_length_b   3.12
_cell_length_c   10.07
_cell_angle_alpha   90.0
_cell_angle_beta   100.3
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   Hf2AlHg
_chemical_formula_sum   'Hf4 Al2 Hg2'
_cell_volume   166.64
_cell_formula_units_Z   2
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  'x, -y, z'
  3  'x+1/2, y+1/2, z'
  4  'x+1/2, -y+1/2, 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  2  0.0  0.0  0.78  1.0
  Hf  Hf1  2  0.0  0.0  0.51  1.0
  Al  Al2  2  0.0  0.0  0.0  1.0
  Hg  Hg3  2  0.0  0.0  0.14  1.0

Hf Hf Al Hg
Hf2HgAl crystallizes in the monoclinic Cm space group. There are two inequivalent Hf sites. In the first Hf site, Hf(1) is bonded to one Hf(2), six equivalent Hf(1), and one Hg(1) atom to form a mixture of distorted edge and corner-sharing HfHf7Hg hexagonal bipyramids. The Hf(1)-Hf(2) bond length is 2.74 Å. All Hf(1)-Hf(1) bond lengths are 3.12 Å. The Hf(1)-Hg(1) bond length is 3.67 Å. In the second Hf site, Hf(2) is bonded in a distorted single-bond geometry to one Hf(1) and one Al(1) atom. The Hf(2)-Al(1) bond length is 2.22 Å. Hg(1) is bonded in a single-bond geometry to one Hf(1) and one Al(1) atom. The Hg(1)-Al(1) bond length is 1.45 Å. Al(1) is bonded in a distorted linear geometry to one Hf(2) and one Hg(1) atom.