FeCrAlO4 is Spinel-derived structured and crystallizes in the orthorhombic Imma space group. Cr(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form CrO6 octahedra that share corners with six equivalent Fe(1)O4 tetrahedra, edges with two equivalent Cr(1)O6 octahedra, and edges with four equivalent Al(1)O6 octahedra. Fe(1) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form FeO4 tetrahedra that share corners with six equivalent Cr(1)O6 octahedra and corners with six equivalent Al(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 55-65°. Al(1) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form AlO6 octahedra that share corners with six equivalent Fe(1)O4 tetrahedra, edges with two equivalent Al(1)O6 octahedra, and edges with four equivalent Cr(1)O6 octahedra. There are two inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Cr(1), one Fe(1), and one Al(1) atom to form a mixture of distorted edge and corner-sharing OAlCr2Fe tetrahedra. In the second O site, O(2) is bonded in a distorted rectangular see-saw-like geometry to one Cr(1), one Fe(1), and two equivalent Al(1) atoms.
FeCrAlO4 is Spinel-derived structured and crystallizes in the orthorhombic Imma space group. Cr(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form CrO6 octahedra that share corners with six equivalent Fe(1)O4 tetrahedra, edges with two equivalent Cr(1)O6 octahedra, and edges with four equivalent Al(1)O6 octahedra. Both Cr(1)-O(2) bond lengths are 2.04 Å. All Cr(1)-O(1) bond lengths are 2.02 Å. Fe(1) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form FeO4 tetrahedra that share corners with six equivalent Cr(1)O6 octahedra and corners with six equivalent Al(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 55-65°. Both Fe(1)-O(1) bond lengths are 2.05 Å. Both Fe(1)-O(2) bond lengths are 2.02 Å. Al(1) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form AlO6 octahedra that share corners with six equivalent Fe(1)O4 tetrahedra, edges with two equivalent Al(1)O6 octahedra, and edges with four equivalent Cr(1)O6 octahedra. Both Al(1)-O(1) bond lengths are 1.92 Å. All Al(1)-O(2) bond lengths are 1.95 Å. There are two inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Cr(1), one Fe(1), and one Al(1) atom to form a mixture of distorted edge and corner-sharing OAlCr2Fe tetrahedra. In the second O site, O(2) is bonded in a distorted rectangular see-saw-like geometry to one Cr(1), one Fe(1), and two equivalent Al(1) atoms.