data_Hf2CrHg
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.73
_cell_length_b   4.73
_cell_length_c   3.35
_cell_angle_alpha   91.25
_cell_angle_beta   91.25
_cell_angle_gamma   92.63
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Hf2CrHg
_chemical_formula_sum   'Hf2 Cr1 Hg1'
_cell_volume   74.88
_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  0.58  0.29  0.67  1.0
  Hf  Hf2  1  0.58  0.71  0.67  1.0
  Cr  Cr0  1  0.0  0.0  0.0  1.0
  Hg  Hg3  1  0.27  0.0  0.0  1.0

data_Hf2CrHg
_symmetry_space_group_name_H-M   P1
_cell_length_a   3.35
_cell_length_b   4.73
_cell_length_c   4.73
_cell_angle_alpha   92.63
_cell_angle_beta   91.25
_cell_angle_gamma   91.25
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Hf2CrHg
_chemical_formula_sum   'Hf2 Cr1 Hg1'
_cell_volume   74.88
_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  0.67  0.58  0.29  1.0
  Hf  Hf1  1  0.67  0.58  0.71  1.0
  Cr  Cr2  1  0.0  0.0  0.0  1.0
  Hg  Hg3  1  0.0  0.27  0.0  1.0

Hf Hf Cr Hg
Hf Hf Cr Hg 0 3 o o + 0 1 o o o 1 3 o + + 2 3 o o o 
Hf2CrHg crystallizes in the triclinic P1 space group. There are two inequivalent Hf sites. In the first Hf site, Hf(1) is bonded in a 1-coordinate geometry to one Hf(2) and one Hg(1) atom. The Hf(1)-Hf(2) bond length is 1.99 Å. The Hf(1)-Hg(1) bond length is 2.28 Å. In the second Hf site, Hf(2) is bonded in a 4-coordinate geometry to one Hf(1), one Cr(1), and two equivalent Hg(1) atoms. The Hf(2)-Cr(1) bond length is 2.57 Å. There is one shorter (2.33 Å) and one longer (3.06 Å) Hf(2)-Hg(1) bond length. Cr(1) is bonded in a distorted single-bond geometry to one Hf(2) and one Hg(1) atom. The Cr(1)-Hg(1) bond length is 1.27 Å. Hg(1) is bonded in a 3-coordinate geometry to one Hf(1), two equivalent Hf(2), and one Cr(1) atom.