data_Hf2ZrAl
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.14
_cell_length_b   3.14
_cell_length_c   8.54
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Hf2ZrAl
_chemical_formula_sum   'Hf2 Zr1 Al1'
_cell_volume   84.21
_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  0.57  0.57  0.99  1.0
  Hf  Hf2  1  0.57  0.57  0.55  1.0
  Zr  Zr3  1  0.0  0.0  0.27  1.0
  Al  Al0  1  0.0  0.0  0.0  1.0

data_Hf2ZrAl
_symmetry_space_group_name_H-M   Cm
_cell_length_a   4.44
_cell_length_b   4.44
_cell_length_c   8.54
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   Hf2ZrAl
_chemical_formula_sum   'Hf4 Zr2 Al2'
_cell_volume   168.41
_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  0.07  0.5  0.55  1.0
  Hf  Hf1  2  0.07  0.5  0.99  1.0
  Zr  Zr2  2  0.0  0.0  0.27  1.0
  Al  Al3  2  0.0  0.0  0.0  1.0

Hf Hf Zr Al
Hf2ZrAl crystallizes in the monoclinic Cm space group. There are two inequivalent Hf sites. In the first Hf site, Hf(1) is bonded in a distorted square co-planar geometry to one Hf(2) and four equivalent Al(1) atoms. The Hf(1)-Hf(2) bond length is 3.79 Å. There are a spread of Hf(1)-Al(1) bond distances ranging from 1.91-2.54 Å. In the second Hf site, Hf(2) is bonded in a 9-coordinate geometry to one Hf(1), four equivalent Hf(2), and four equivalent Zr(1) atoms. All Hf(2)-Hf(2) bond lengths are 3.14 Å. There are a spread of Hf(2)-Zr(1) bond distances ranging from 3.05-3.47 Å. Zr(1) is bonded in a single-bond geometry to four equivalent Hf(2) and one Al(1) atom. The Zr(1)-Al(1) bond length is 2.28 Å. Al(1) is bonded to four equivalent Hf(1) and one Zr(1) atom to form a mixture of edge and corner-sharing AlHf4Zr square pyramids.