NiCr2O4 is Spinel structured and crystallizes in the monoclinic C2/m space group. There are three inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to two equivalent O(3) and four equivalent O(2) atoms to form CrO6 octahedra that share corners with six equivalent Ni(1)O4 tetrahedra, edges with two equivalent Cr(2)O6 octahedra, and edges with four equivalent Cr(3)O6 octahedra. In the second Cr site, Cr(2) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form CrO6 octahedra that share corners with six equivalent Ni(1)O4 tetrahedra, edges with two equivalent Cr(1)O6 octahedra, and edges with four equivalent Cr(3)O6 octahedra. In the third Cr site, Cr(3) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form CrO6 octahedra that share corners with six equivalent Ni(1)O4 tetrahedra, edges with two equivalent Cr(1)O6 octahedra, edges with two equivalent Cr(2)O6 octahedra, and edges with two equivalent Cr(3)O6 octahedra. Ni(1) is bonded to one O(1), one O(3), and two equivalent O(2) atoms to form NiO4 tetrahedra that share corners with three equivalent Cr(1)O6 octahedra, corners with three equivalent Cr(2)O6 octahedra, and corners with six equivalent Cr(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 53-62°. There are three inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to one Cr(2), two equivalent Cr(3), and one Ni(1) atom. In the second O site, O(2) is bonded in a rectangular see-saw-like geometry to one Cr(1), one Cr(2), one Cr(3), and one Ni(1) atom. In the third O site, O(3) is bonded in a rectangular see-saw-like geometry to one Cr(1), two equivalent Cr(3), and one Ni(1) atom.
NiCr2O4 is Spinel structured and crystallizes in the monoclinic C2/m space group. There are three inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to two equivalent O(3) and four equivalent O(2) atoms to form CrO6 octahedra that share corners with six equivalent Ni(1)O4 tetrahedra, edges with two equivalent Cr(2)O6 octahedra, and edges with four equivalent Cr(3)O6 octahedra. Both Cr(1)-O(3) bond lengths are 2.03 Å. All Cr(1)-O(2) bond lengths are 2.03 Å. In the second Cr site, Cr(2) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form CrO6 octahedra that share corners with six equivalent Ni(1)O4 tetrahedra, edges with two equivalent Cr(1)O6 octahedra, and edges with four equivalent Cr(3)O6 octahedra. Both Cr(2)-O(1) bond lengths are 2.02 Å. All Cr(2)-O(2) bond lengths are 2.02 Å. In the third Cr site, Cr(3) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form CrO6 octahedra that share corners with six equivalent Ni(1)O4 tetrahedra, edges with two equivalent Cr(1)O6 octahedra, edges with two equivalent Cr(2)O6 octahedra, and edges with two equivalent Cr(3)O6 octahedra. Both Cr(3)-O(1) bond lengths are 2.02 Å. Both Cr(3)-O(2) bond lengths are 2.02 Å. Both Cr(3)-O(3) bond lengths are 2.02 Å. Ni(1) is bonded to one O(1), one O(3), and two equivalent O(2) atoms to form NiO4 tetrahedra that share corners with three equivalent Cr(1)O6 octahedra, corners with three equivalent Cr(2)O6 octahedra, and corners with six equivalent Cr(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 53-62°. The Ni(1)-O(1) bond length is 1.99 Å. The Ni(1)-O(3) bond length is 1.99 Å. Both Ni(1)-O(2) bond lengths are 1.99 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to one Cr(2), two equivalent Cr(3), and one Ni(1) atom. In the second O site, O(2) is bonded in a rectangular see-saw-like geometry to one Cr(1), one Cr(2), one Cr(3), and one Ni(1) atom. In the third O site, O(3) is bonded in a rectangular see-saw-like geometry to one Cr(1), two equivalent Cr(3), and one Ni(1) atom.