The crystal structure described by NiCo2O4 is Spinel structured and crystallizes in the trigonal R-3m space group. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded to six equivalent O(2) atoms to form CoO6 octahedra that share corners with six equivalent Ni(1)O4 tetrahedra and edges with six equivalent Co(2)O6 octahedra. In the second Co site, Co(2) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form CoO6 octahedra that share corners with six equivalent Ni(1)O4 tetrahedra, edges with two equivalent Co(1)O6 octahedra, and edges with four equivalent Co(2)O6 octahedra. Ni(1) is bonded to one O(1) and three equivalent O(2) atoms to form NiO4 tetrahedra that share corners with three equivalent Co(1)O6 octahedra and corners with nine equivalent Co(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 59-60°. There are two inequivalent O sites. In the first O site, O(1) is bonded to three equivalent Co(2) and one Ni(1) atom to form a mixture of distorted corner and edge-sharing OCo3Ni tetrahedra. In the second O site, O(2) is bonded to one Co(1), two equivalent Co(2), and one Ni(1) atom to form a mixture of distorted corner and edge-sharing OCo3Ni trigonal pyramids. is represented by the CIF card [CIF]
data_Co2NiO4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.808
_cell_length_b   5.808
_cell_length_c   5.808
_cell_angle_alpha   58.979
_cell_angle_beta   58.979
_cell_angle_gamma   58.979
_symmetry_Int_Tables_number   1
_cell_volume   135.291
_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
  Co  Co0  1  0.000  0.000  0.000  1.0
  Co  Co1  1  0.000  0.500  0.000  1.0
  Co  Co2  1  0.500  0.000  0.000  1.0
  Co  Co3  1  0.000  0.000  0.500  1.0
  Ni  Ni4  1  0.625  0.625  0.625  1.0
  Ni  Ni5  1  0.375  0.375  0.375  1.0
  O  O6  1  0.233  0.233  0.233  1.0
  O  O7  1  0.235  0.792  0.235  1.0
  O  O8  1  0.792  0.235  0.235  1.0
  O  O9  1  0.235  0.235  0.792  1.0
  O  O10  1  0.767  0.767  0.767  1.0
  O  O11  1  0.765  0.208  0.765  1.0
  O  O12  1  0.208  0.765  0.765  1.0
  O  O13  1  0.765  0.765  0.208  1.0
[/CIF]
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The crystal structure described by NiCo2O4 is Spinel structured and crystallizes in the trigonal R-3m space group. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded to six equivalent O(2) atoms to form CoO6 octahedra that share corners with six equivalent Ni(1)O4 tetrahedra and edges with six equivalent Co(2)O6 octahedra. In the second Co site, Co(2) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form CoO6 octahedra that share corners with six equivalent Ni(1)O4 tetrahedra, edges with two equivalent Co(1)O6 octahedra, and edges with four equivalent Co(2)O6 octahedra. Ni(1) is bonded to one O(1) and three equivalent O(2) atoms to form NiO4 tetrahedra that share corners with three equivalent Co(1)O6 octahedra and corners with nine equivalent Co(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 59-60°. There are two inequivalent O sites. In the first O site, O(1) is bonded to three equivalent Co(2) and one Ni(1) atom to form a mixture of distorted corner and edge-sharing OCo3Ni tetrahedra. In the second O site, O(2) is bonded to one Co(1), two equivalent Co(2), and one Ni(1) atom to form a mixture of distorted corner and edge-sharing OCo3Ni trigonal pyramids. is represented by the CIF card [CIF]
data_Co2NiO4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.808
_cell_length_b   5.808
_cell_length_c   5.808
_cell_angle_alpha   58.979
_cell_angle_beta   58.979
_cell_angle_gamma   58.979
_symmetry_Int_Tables_number   1
_cell_volume   135.291
_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
  Co  Co0  1  0.000  0.000  0.000  1.0
  Co  Co1  1  0.000  0.500  0.000  1.0
  Co  Co2  1  0.500  0.000  0.000  1.0
  Co  Co3  1  0.000  0.000  0.500  1.0
  Ni  Ni4  1  0.625  0.625  0.625  1.0
  Ni  Ni5  1  0.375  0.375  0.375  1.0
  O  O6  1  0.233  0.233  0.233  1.0
  O  O7  1  0.235  0.792  0.235  1.0
  O  O8  1  0.792  0.235  0.235  1.0
  O  O9  1  0.235  0.235  0.792  1.0
  O  O10  1  0.767  0.767  0.767  1.0
  O  O11  1  0.765  0.208  0.765  1.0
  O  O12  1  0.208  0.765  0.765  1.0
  O  O13  1  0.765  0.765  0.208  1.0
[/CIF]
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