The crystal structure described by NiAl2O4 is Spinel structured and crystallizes in the tetragonal I4_1md space group. Ni(1) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form NiO4 tetrahedra that share corners with twelve equivalent Al(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 58-63°. Al(1) is bonded to three equivalent O(1) and three equivalent O(2) atoms to form AlO6 octahedra that share corners with six equivalent Ni(1)O4 tetrahedra and edges with six equivalent Al(1)O6 octahedra. There are two inequivalent O sites. In the first O site, O(1) is bonded to one Ni(1) and three equivalent Al(1) atoms to form a mixture of distorted edge and corner-sharing OAl3Ni trigonal pyramids. In the second O site, O(2) is bonded to one Ni(1) and three equivalent Al(1) atoms to form a mixture of distorted edge and corner-sharing OAl3Ni trigonal pyramids. is represented by the Crystallographic Information File (CIF) [CIF]
data_Al2NiO4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.816
_cell_length_b   5.752
_cell_length_c   5.753
_cell_angle_alpha   91.213
_cell_angle_beta   120.336
_cell_angle_gamma   59.654
_symmetry_Int_Tables_number   1
_cell_volume   136.092
_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
  Al  Al0  1  0.502  0.500  0.500  1.0
  Al  Al1  1  0.998  0.500  0.500  1.0
  Al  Al2  1  0.498  0.501  0.998  1.0
  Al  Al3  1  0.002  0.998  0.501  1.0
  Ni  Ni4  1  0.250  0.131  0.130  1.0
  Ni  Ni5  1  0.750  0.880  0.880  1.0
  O  O6  1  0.035  0.725  0.295  1.0
  O  O7  1  0.972  0.265  0.709  1.0
  O  O8  1  0.465  0.295  0.726  1.0
  O  O9  1  0.528  0.709  0.265  1.0
  O  O10  1  0.028  0.737  0.738  1.0
  O  O11  1  0.965  0.260  0.260  1.0
  O  O12  1  0.472  0.738  0.737  1.0
  O  O13  1  0.535  0.260  0.260  1.0
[/CIF]
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The crystal structure described by NiAl2O4 is Spinel structured and crystallizes in the tetragonal I4_1md space group. Ni(1) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form NiO4 tetrahedra that share corners with twelve equivalent Al(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 58-63°. Al(1) is bonded to three equivalent O(1) and three equivalent O(2) atoms to form AlO6 octahedra that share corners with six equivalent Ni(1)O4 tetrahedra and edges with six equivalent Al(1)O6 octahedra. There are two inequivalent O sites. In the first O site, O(1) is bonded to one Ni(1) and three equivalent Al(1) atoms to form a mixture of distorted edge and corner-sharing OAl3Ni trigonal pyramids. In the second O site, O(2) is bonded to one Ni(1) and three equivalent Al(1) atoms to form a mixture of distorted edge and corner-sharing OAl3Ni trigonal pyramids. is represented by the Crystallographic Information File (CIF) [CIF]
data_Al2NiO4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.816
_cell_length_b   5.752
_cell_length_c   5.753
_cell_angle_alpha   91.213
_cell_angle_beta   120.336
_cell_angle_gamma   59.654
_symmetry_Int_Tables_number   1
_cell_volume   136.092
_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
  Al  Al0  1  0.502  0.500  0.500  1.0
  Al  Al1  1  0.998  0.500  0.500  1.0
  Al  Al2  1  0.498  0.501  0.998  1.0
  Al  Al3  1  0.002  0.998  0.501  1.0
  Ni  Ni4  1  0.250  0.131  0.130  1.0
  Ni  Ni5  1  0.750  0.880  0.880  1.0
  O  O6  1  0.035  0.725  0.295  1.0
  O  O7  1  0.972  0.265  0.709  1.0
  O  O8  1  0.465  0.295  0.726  1.0
  O  O9  1  0.528  0.709  0.265  1.0
  O  O10  1  0.028  0.737  0.738  1.0
  O  O11  1  0.965  0.260  0.260  1.0
  O  O12  1  0.472  0.738  0.737  1.0
  O  O13  1  0.535  0.260  0.260  1.0
[/CIF]
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