NiGa2O4 is Spinel-like structured and crystallizes in the trigonal R3m space group. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to one O(4) and three equivalent O(3) atoms to form NiO4 tetrahedra that share corners with three equivalent Ni(2)O6 octahedra and corners with nine equivalent Ga(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 56-60°. In the second Ni site, Ni(2) is bonded to three equivalent O(1) and three equivalent O(3) atoms to form NiO6 octahedra that share corners with three equivalent Ni(1)O4 tetrahedra, corners with three equivalent Ga(2)O4 tetrahedra, and edges with six equivalent Ga(1)O6 octahedra. There are two inequivalent Ga sites. In the first Ga site, Ga(1) is bonded to one O(2), one O(4), two equivalent O(1), and two equivalent O(3) atoms to form GaO6 octahedra that share corners with three equivalent Ni(1)O4 tetrahedra, corners with three equivalent Ga(2)O4 tetrahedra, edges with two equivalent Ni(2)O6 octahedra, and edges with four equivalent Ga(1)O6 octahedra. In the second Ga site, Ga(2) is bonded to one O(2) and three equivalent O(1) atoms to form GaO4 tetrahedra that share corners with three equivalent Ni(2)O6 octahedra and corners with nine equivalent Ga(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 57-58°. There are four inequivalent O sites. In the first O site, O(1) is bonded to one Ni(2), one Ga(2), and two equivalent Ga(1) atoms to form a mixture of distorted edge and corner-sharing OGa3Ni trigonal pyramids. In the second O site, O(2) is bonded in a distorted rectangular see-saw-like geometry to one Ga(2) and three equivalent Ga(1) atoms. In the third O site, O(3) is bonded in a rectangular see-saw-like geometry to one Ni(1), one Ni(2), and two equivalent Ga(1) atoms. In the fourth O site, O(4) is bonded in a distorted rectangular see-saw-like geometry to one Ni(1) and three equivalent Ga(1) atoms.
NiGa2O4 is Spinel-like structured and crystallizes in the trigonal R3m space group. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to one O(4) and three equivalent O(3) atoms to form NiO4 tetrahedra that share corners with three equivalent Ni(2)O6 octahedra and corners with nine equivalent Ga(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 56-60°. The Ni(1)-O(4) bond length is 2.00 Å. All Ni(1)-O(3) bond lengths are 1.96 Å. In the second Ni site, Ni(2) is bonded to three equivalent O(1) and three equivalent O(3) atoms to form NiO6 octahedra that share corners with three equivalent Ni(1)O4 tetrahedra, corners with three equivalent Ga(2)O4 tetrahedra, and edges with six equivalent Ga(1)O6 octahedra. All Ni(2)-O(1) bond lengths are 2.08 Å. All Ni(2)-O(3) bond lengths are 2.05 Å. There are two inequivalent Ga sites. In the first Ga site, Ga(1) is bonded to one O(2), one O(4), two equivalent O(1), and two equivalent O(3) atoms to form GaO6 octahedra that share corners with three equivalent Ni(1)O4 tetrahedra, corners with three equivalent Ga(2)O4 tetrahedra, edges with two equivalent Ni(2)O6 octahedra, and edges with four equivalent Ga(1)O6 octahedra. The Ga(1)-O(2) bond length is 2.07 Å. The Ga(1)-O(4) bond length is 1.99 Å. Both Ga(1)-O(1) bond lengths are 2.04 Å. Both Ga(1)-O(3) bond lengths are 1.96 Å. In the second Ga site, Ga(2) is bonded to one O(2) and three equivalent O(1) atoms to form GaO4 tetrahedra that share corners with three equivalent Ni(2)O6 octahedra and corners with nine equivalent Ga(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 57-58°. The Ga(2)-O(2) bond length is 1.96 Å. All Ga(2)-O(1) bond lengths are 1.90 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded to one Ni(2), one Ga(2), and two equivalent Ga(1) atoms to form a mixture of distorted edge and corner-sharing OGa3Ni trigonal pyramids. In the second O site, O(2) is bonded in a distorted rectangular see-saw-like geometry to one Ga(2) and three equivalent Ga(1) atoms. In the third O site, O(3) is bonded in a rectangular see-saw-like geometry to one Ni(1), one Ni(2), and two equivalent Ga(1) atoms. In the fourth O site, O(4) is bonded in a distorted rectangular see-saw-like geometry to one Ni(1) and three equivalent Ga(1) atoms.