The material structure described by HfNi2Al5 crystallizes in the tetragonal I4/mmm space group. Hf(1) is bonded to four equivalent Al(2) and eight Al(1,1) atoms to form HfAl12 cuboctahedra that share corners with four equivalent Hf(1)Al12 cuboctahedra, faces with four equivalent Hf(1)Al12 cuboctahedra, and faces with four equivalent Al(2)Hf4Al8 cuboctahedra. Ni(1) is bonded in a body-centered cubic geometry to eight equivalent Al(1) atoms. There are three inequivalent Al sites. In the first Al site, Al(1) is bonded in a 6-coordinate geometry to two equivalent Hf(1), four equivalent Ni(1), and two equivalent Al(2) atoms. In the second Al site, Al(2) is bonded to four equivalent Hf(1) and eight Al(1,1) atoms to form distorted AlHf4Al8 cuboctahedra that share corners with four equivalent Al(2)Hf4Al8 cuboctahedra, faces with four equivalent Hf(1)Al12 cuboctahedra, and faces with four equivalent Al(2)Hf4Al8 cuboctahedra. In the third Al site, Al(1) is bonded in a 6-coordinate geometry to two equivalent Hf(1), four equivalent Ni(1), and two equivalent Al(2) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_HfAl5Ni2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.980
_cell_length_b   3.980
_cell_length_c   7.730
_cell_angle_alpha   104.919
_cell_angle_beta   104.919
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   114.049
_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  0.000  0.000  0.000  1.0
  Al  Al1  1  0.147  0.647  0.295  1.0
  Al  Al2  1  0.853  0.353  0.705  1.0
  Al  Al3  1  0.647  0.147  0.295  1.0
  Al  Al4  1  0.353  0.853  0.705  1.0
  Al  Al5  1  0.500  0.500  0.000  1.0
  Ni  Ni6  1  0.240  0.240  0.480  1.0
  Ni  Ni7  1  0.760  0.760  0.520  1.0
[/CIF]
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The material structure described by HfNi2Al5 crystallizes in the tetragonal I4/mmm space group. Hf(1) is bonded to four equivalent Al(2) and eight Al(1,1) atoms to form HfAl12 cuboctahedra that share corners with four equivalent Hf(1)Al12 cuboctahedra, faces with four equivalent Hf(1)Al12 cuboctahedra, and faces with four equivalent Al(2)Hf4Al8 cuboctahedra. Ni(1) is bonded in a body-centered cubic geometry to eight equivalent Al(1) atoms. There are three inequivalent Al sites. In the first Al site, Al(1) is bonded in a 6-coordinate geometry to two equivalent Hf(1), four equivalent Ni(1), and two equivalent Al(2) atoms. In the second Al site, Al(2) is bonded to four equivalent Hf(1) and eight Al(1,1) atoms to form distorted AlHf4Al8 cuboctahedra that share corners with four equivalent Al(2)Hf4Al8 cuboctahedra, faces with four equivalent Hf(1)Al12 cuboctahedra, and faces with four equivalent Al(2)Hf4Al8 cuboctahedra. In the third Al site, Al(1) is bonded in a 6-coordinate geometry to two equivalent Hf(1), four equivalent Ni(1), and two equivalent Al(2) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_HfAl5Ni2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.980
_cell_length_b   3.980
_cell_length_c   7.730
_cell_angle_alpha   104.919
_cell_angle_beta   104.919
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   114.049
_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  0.000  0.000  0.000  1.0
  Al  Al1  1  0.147  0.647  0.295  1.0
  Al  Al2  1  0.853  0.353  0.705  1.0
  Al  Al3  1  0.647  0.147  0.295  1.0
  Al  Al4  1  0.353  0.853  0.705  1.0
  Al  Al5  1  0.500  0.500  0.000  1.0
  Ni  Ni6  1  0.240  0.240  0.480  1.0
  Ni  Ni7  1  0.760  0.760  0.520  1.0
[/CIF]
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