Al3(O2F)2 crystallizes in the orthorhombic Pnma space group. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to one O(1), one O(2), two equivalent O(3), and two equivalent F(1) atoms to form AlO4F2 octahedra that share corners with two equivalent Al(1)O4F2 octahedra, corners with four equivalent Al(2)O4 tetrahedra, and edges with two equivalent Al(1)O4F2 octahedra. The corner-sharing octahedral tilt angles are 36°. In the second Al site, Al(2) is bonded to one O(1), one O(2), and two equivalent O(3) atoms to form corner-sharing AlO4 tetrahedra. The corner-sharing octahedral tilt angles range from 49-54°. There are three inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one Al(2) and two equivalent Al(1) atoms. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Al(2) and two equivalent Al(1) atoms. In the third O site, O(3) is bonded in a trigonal planar geometry to one Al(2) and two equivalent Al(1) atoms. F(1) is bonded in a bent 150 degrees geometry to two equivalent Al(1) atoms.
Al3(O2F)2 crystallizes in the orthorhombic Pnma space group. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to one O(1), one O(2), two equivalent O(3), and two equivalent F(1) atoms to form AlO4F2 octahedra that share corners with two equivalent Al(1)O4F2 octahedra, corners with four equivalent Al(2)O4 tetrahedra, and edges with two equivalent Al(1)O4F2 octahedra. The corner-sharing octahedral tilt angles are 36°. The Al(1)-O(1) bond length is 1.86 Å. The Al(1)-O(2) bond length is 1.98 Å. There is one shorter (1.84 Å) and one longer (1.86 Å) Al(1)-O(3) bond length. Both Al(1)-F(1) bond lengths are 1.83 Å. In the second Al site, Al(2) is bonded to one O(1), one O(2), and two equivalent O(3) atoms to form corner-sharing AlO4 tetrahedra. The corner-sharing octahedral tilt angles range from 49-54°. The Al(2)-O(1) bond length is 1.75 Å. The Al(2)-O(2) bond length is 1.83 Å. Both Al(2)-O(3) bond lengths are 1.74 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one Al(2) and two equivalent Al(1) atoms. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Al(2) and two equivalent Al(1) atoms. In the third O site, O(3) is bonded in a trigonal planar geometry to one Al(2) and two equivalent Al(1) atoms. F(1) is bonded in a bent 150 degrees geometry to two equivalent Al(1) atoms.