The crystal structure described by NiAl2O4 is Spinel structured and crystallizes in the orthorhombic Pmn2_1 space group. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to one O(1), one O(2), and two equivalent O(3) atoms to form NiO4 tetrahedra that share corners with three equivalent Al(2)O6 octahedra, corners with three equivalent Al(3)O6 octahedra, and corners with six equivalent Al(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 58-64°. In the second Ni site, Ni(1) is bonded to one O(1), one O(2), and two equivalent O(3) atoms to form NiO4 tetrahedra that share corners with three equivalent Al(2)O6 octahedra, corners with three equivalent Al(3)O6 octahedra, and corners with six equivalent Al(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 58-64°. There are three inequivalent Al sites. In the first Al site, Al(1) is bonded to two O(1,1); two O(2,2); and two O(3,3) atoms to form AlO6 octahedra that share corners with six Ni(1,1)O4 tetrahedra; edges with two equivalent Al(1)O6 octahedra; edges with two equivalent Al(2)O6 octahedra; and edges with two equivalent Al(3)O6 octahedra. In the second Al site, Al(2) is bonded to two O(2,2) and four O(3,3) atoms to form AlO6 octahedra that share corners with six Ni(1,1)O4 tetrahedra; edges with two equivalent Al(3)O6 octahedra; and edges with four equivalent Al(1)O6 octahedra. In the third Al site, Al(3) is bonded to two O(1,1) and four O(3,3) atoms to form AlO6 octahedra that share corners with six Ni(1,1)O4 tetrahedra; edges with two equivalent Al(2)O6 octahedra; and edges with four equivalent Al(1)O6 octahedra. There are six inequivalent O sites. In the first O site, O(1) is bonded in a distorted rectangular see-saw-like geometry to one Ni(1), one Al(3), and two equivalent Al(1) atoms. In the second O site, O(2) is bonded in a distorted rectangular see-saw-like geometry to one Ni(1), one Al(2), and two equivalent Al(1) atoms. In the third O site, O(2) is bonded in a distorted rectangular see-saw-like geometry to one Ni(1), one Al(2), and two equivalent Al(1) atoms. In the fourth O site, O(1) is bonded in a distorted rectangular see-saw-like geometry to one Ni(1), one Al(3), and two equivalent Al(1) atoms. In the fifth O site, O(3) is bonded to one Ni(1), one Al(1), one Al(2), and one Al(3) atom to form a mixture of distorted edge and corner-sharing OAl3Ni trigonal pyramids. In the sixth O site, O(3) is bonded to one Ni(1), one Al(1), one Al(2), and one Al(3) atom to form a mixture of distorted edge and corner-sharing OAl3Ni trigonal pyramids. is represented by the CIF card [CIF]
data_Al2NiO4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.753
_cell_length_b   5.756
_cell_length_c   5.757
_cell_angle_alpha   88.713
_cell_angle_beta   60.028
_cell_angle_gamma   60.024
_symmetry_Int_Tables_number   1
_cell_volume   136.337
_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  0.500  0.500  0.500  1.0
  Al  Al1  1  0.500  0.000  0.500  1.0
  Al  Al2  1  0.000  0.500  0.500  1.0
  Al  Al3  1  1.000  0.500  0.000  1.0
  Ni  Ni4  1  0.750  0.118  0.882  1.0
  Ni  Ni5  1  0.250  0.882  0.118  1.0
  O  O6  1  0.034  0.704  0.728  1.0
  O  O7  1  0.966  0.296  0.272  1.0
  O  O8  1  0.029  0.261  0.739  1.0
  O  O9  1  0.971  0.739  0.261  1.0
  O  O10  1  0.471  0.261  0.739  1.0
  O  O11  1  0.466  0.272  0.296  1.0
  O  O12  1  0.534  0.728  0.704  1.0
  O  O13  1  0.529  0.739  0.261  1.0
[/CIF]
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The crystal structure described by NiAl2O4 is Spinel structured and crystallizes in the orthorhombic Pmn2_1 space group. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to one O(1), one O(2), and two equivalent O(3) atoms to form NiO4 tetrahedra that share corners with three equivalent Al(2)O6 octahedra, corners with three equivalent Al(3)O6 octahedra, and corners with six equivalent Al(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 58-64°. In the second Ni site, Ni(1) is bonded to one O(1), one O(2), and two equivalent O(3) atoms to form NiO4 tetrahedra that share corners with three equivalent Al(2)O6 octahedra, corners with three equivalent Al(3)O6 octahedra, and corners with six equivalent Al(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 58-64°. There are three inequivalent Al sites. In the first Al site, Al(1) is bonded to two O(1,1); two O(2,2); and two O(3,3) atoms to form AlO6 octahedra that share corners with six Ni(1,1)O4 tetrahedra; edges with two equivalent Al(1)O6 octahedra; edges with two equivalent Al(2)O6 octahedra; and edges with two equivalent Al(3)O6 octahedra. In the second Al site, Al(2) is bonded to two O(2,2) and four O(3,3) atoms to form AlO6 octahedra that share corners with six Ni(1,1)O4 tetrahedra; edges with two equivalent Al(3)O6 octahedra; and edges with four equivalent Al(1)O6 octahedra. In the third Al site, Al(3) is bonded to two O(1,1) and four O(3,3) atoms to form AlO6 octahedra that share corners with six Ni(1,1)O4 tetrahedra; edges with two equivalent Al(2)O6 octahedra; and edges with four equivalent Al(1)O6 octahedra. There are six inequivalent O sites. In the first O site, O(1) is bonded in a distorted rectangular see-saw-like geometry to one Ni(1), one Al(3), and two equivalent Al(1) atoms. In the second O site, O(2) is bonded in a distorted rectangular see-saw-like geometry to one Ni(1), one Al(2), and two equivalent Al(1) atoms. In the third O site, O(2) is bonded in a distorted rectangular see-saw-like geometry to one Ni(1), one Al(2), and two equivalent Al(1) atoms. In the fourth O site, O(1) is bonded in a distorted rectangular see-saw-like geometry to one Ni(1), one Al(3), and two equivalent Al(1) atoms. In the fifth O site, O(3) is bonded to one Ni(1), one Al(1), one Al(2), and one Al(3) atom to form a mixture of distorted edge and corner-sharing OAl3Ni trigonal pyramids. In the sixth O site, O(3) is bonded to one Ni(1), one Al(1), one Al(2), and one Al(3) atom to form a mixture of distorted edge and corner-sharing OAl3Ni trigonal pyramids. is represented by the CIF card [CIF]
data_Al2NiO4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.753
_cell_length_b   5.756
_cell_length_c   5.757
_cell_angle_alpha   88.713
_cell_angle_beta   60.028
_cell_angle_gamma   60.024
_symmetry_Int_Tables_number   1
_cell_volume   136.337
_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  0.500  0.500  0.500  1.0
  Al  Al1  1  0.500  0.000  0.500  1.0
  Al  Al2  1  0.000  0.500  0.500  1.0
  Al  Al3  1  1.000  0.500  0.000  1.0
  Ni  Ni4  1  0.750  0.118  0.882  1.0
  Ni  Ni5  1  0.250  0.882  0.118  1.0
  O  O6  1  0.034  0.704  0.728  1.0
  O  O7  1  0.966  0.296  0.272  1.0
  O  O8  1  0.029  0.261  0.739  1.0
  O  O9  1  0.971  0.739  0.261  1.0
  O  O10  1  0.471  0.261  0.739  1.0
  O  O11  1  0.466  0.272  0.296  1.0
  O  O12  1  0.534  0.728  0.704  1.0
  O  O13  1  0.529  0.739  0.261  1.0
[/CIF]
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