Materials Data on Al3(O2F)2 by Materials Project
Al3(O2F)2 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. there are two inequivalent Al sites. In the first Al site, Al is bonded to four O and two equivalent F atoms to form AlO4F2 octahedra that share corners with two equivalent AlO4F2 octahedra, corners with four equivalent AlO4 tetrahedra, and edges with two equivalent AlO4F2 octahedra. The corner-sharing octahedral tilt angles are 33°. There is three shorter (1.89 Å) and one longer (1.94 Å) Al–O bond length. Both Al–F bond lengths are 1.85 Å. In the second Al site, Al is bonded to four O atoms to form corner-sharing AlO4 tetrahedra. The corner-sharing octahedra tilt angles range from 50–53°. There is three shorter (1.77 Å) and one longer (1.79 Å) Al–O bond length. There are three inequivalent O sites. In the first O site, O is bonded in a trigonal planar geometry to three Al atoms. In the second O site, O is bonded in a distorted trigonal planar geometry to three Al atoms. In the third O site, O is bonded in a trigonal planar geometry to three Al atoms. F is bonded in a bent 150 degrees geometry to two equivalent Al atoms.