The crystal structure described by Hf3Al3C5 crystallizes in the hexagonal P6_3/mmc space group. There are two inequivalent Hf sites. In the first Hf site, Hf(1) is bonded to three equivalent C(1) and three equivalent C(2) atoms to form HfC6 octahedra that share corners with three equivalent Hf(2)C6 octahedra, corners with three equivalent Al(1)C4 tetrahedra, edges with three equivalent Hf(2)C6 octahedra, edges with six equivalent Hf(1)C6 octahedra, and edges with three equivalent Al(1)C4 tetrahedra. The corner-sharing octahedral tilt angles are 3°. In the second Hf site, Hf(2) is bonded to six equivalent C(1) atoms to form a mixture of edge and corner-sharing HfC6 octahedra. The corner-sharing octahedral tilt angles are 3°. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to one C(3) and three equivalent C(2) atoms to form AlC4 tetrahedra that share corners with three equivalent Hf(1)C6 octahedra, corners with seven equivalent Al(1)C4 tetrahedra, and edges with three equivalent Hf(1)C6 octahedra. The corner-sharing octahedral tilt angles are 19°. In the second Al site, Al(2) is bonded in a trigonal planar geometry to three equivalent C(3) atoms. There are three inequivalent C sites. In the first C site, C(1) is bonded to three equivalent Hf(1) and three equivalent Hf(2) atoms to form a mixture of edge and corner-sharing CHf6 octahedra. The corner-sharing octahedra are not tilted. In the second C site, C(2) is bonded in a 6-coordinate geometry to three equivalent Hf(1) and three equivalent Al(1) atoms. In the third C site, C(3) is bonded to two equivalent Al(1) and three equivalent Al(2) atoms to form corner-sharing CAl5 trigonal bipyramids. is represented by the Crystallographic Information File (CIF) [CIF]
data_Hf3Al3C5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.313
_cell_length_b   3.313
_cell_length_c   27.340
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   259.921
_cell_formula_units_Z   2
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  0.333  0.667  0.594  1.0
  Hf  Hf1  1  0.333  0.667  0.906  1.0
  Hf  Hf2  1  0.667  0.333  0.094  1.0
  Hf  Hf3  1  0.667  0.333  0.406  1.0
  Hf  Hf4  1  1.000  0.000  1.000  1.0
  Hf  Hf5  1  0.000  1.000  0.500  1.0
  Al  Al6  1  0.667  0.333  0.824  1.0
  Al  Al7  1  0.333  0.667  0.324  1.0
  Al  Al8  1  0.000  1.000  0.750  1.0
  Al  Al9  1  0.333  0.667  0.176  1.0
  Al  Al10  1  0.667  0.333  0.676  1.0
  Al  Al11  1  1.000  0.000  0.250  1.0
  C  C12  1  0.333  0.667  0.050  1.0
  C  C13  1  1.000  1.000  0.849  1.0
  C  C14  1  1.000  0.000  0.349  1.0
  C  C15  1  0.667  0.333  0.950  1.0
  C  C16  1  0.667  0.333  0.550  1.0
  C  C17  1  0.333  0.667  0.450  1.0
  C  C18  1  0.000  1.000  0.651  1.0
  C  C19  1  1.000  0.000  0.151  1.0
  C  C20  1  0.667  0.333  0.750  1.0
  C  C21  1  0.333  0.667  0.250  1.0
[/CIF]
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The crystal structure described by Hf3Al3C5 crystallizes in the hexagonal P6_3/mmc space group. There are two inequivalent Hf sites. In the first Hf site, Hf(1) is bonded to three equivalent C(1) and three equivalent C(2) atoms to form HfC6 octahedra that share corners with three equivalent Hf(2)C6 octahedra, corners with three equivalent Al(1)C4 tetrahedra, edges with three equivalent Hf(2)C6 octahedra, edges with six equivalent Hf(1)C6 octahedra, and edges with three equivalent Al(1)C4 tetrahedra. The corner-sharing octahedral tilt angles are 3°. In the second Hf site, Hf(2) is bonded to six equivalent C(1) atoms to form a mixture of edge and corner-sharing HfC6 octahedra. The corner-sharing octahedral tilt angles are 3°. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to one C(3) and three equivalent C(2) atoms to form AlC4 tetrahedra that share corners with three equivalent Hf(1)C6 octahedra, corners with seven equivalent Al(1)C4 tetrahedra, and edges with three equivalent Hf(1)C6 octahedra. The corner-sharing octahedral tilt angles are 19°. In the second Al site, Al(2) is bonded in a trigonal planar geometry to three equivalent C(3) atoms. There are three inequivalent C sites. In the first C site, C(1) is bonded to three equivalent Hf(1) and three equivalent Hf(2) atoms to form a mixture of edge and corner-sharing CHf6 octahedra. The corner-sharing octahedra are not tilted. In the second C site, C(2) is bonded in a 6-coordinate geometry to three equivalent Hf(1) and three equivalent Al(1) atoms. In the third C site, C(3) is bonded to two equivalent Al(1) and three equivalent Al(2) atoms to form corner-sharing CAl5 trigonal bipyramids. is represented by the Crystallographic Information File (CIF) [CIF]
data_Hf3Al3C5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.313
_cell_length_b   3.313
_cell_length_c   27.340
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   259.921
_cell_formula_units_Z   2
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  0.333  0.667  0.594  1.0
  Hf  Hf1  1  0.333  0.667  0.906  1.0
  Hf  Hf2  1  0.667  0.333  0.094  1.0
  Hf  Hf3  1  0.667  0.333  0.406  1.0
  Hf  Hf4  1  1.000  0.000  1.000  1.0
  Hf  Hf5  1  0.000  1.000  0.500  1.0
  Al  Al6  1  0.667  0.333  0.824  1.0
  Al  Al7  1  0.333  0.667  0.324  1.0
  Al  Al8  1  0.000  1.000  0.750  1.0
  Al  Al9  1  0.333  0.667  0.176  1.0
  Al  Al10  1  0.667  0.333  0.676  1.0
  Al  Al11  1  1.000  0.000  0.250  1.0
  C  C12  1  0.333  0.667  0.050  1.0
  C  C13  1  1.000  1.000  0.849  1.0
  C  C14  1  1.000  0.000  0.349  1.0
  C  C15  1  0.667  0.333  0.950  1.0
  C  C16  1  0.667  0.333  0.550  1.0
  C  C17  1  0.333  0.667  0.450  1.0
  C  C18  1  0.000  1.000  0.651  1.0
  C  C19  1  1.000  0.000  0.151  1.0
  C  C20  1  0.667  0.333  0.750  1.0
  C  C21  1  0.333  0.667  0.250  1.0
[/CIF]
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