Materials Data on NaAlPO4F by Materials Project
NaAlPO4F crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. Na1+ is bonded in a 7-coordinate geometry to six O2- and one F1- atom. There are a spread of Na–O bond distances ranging from 2.33–2.60 Å. The Na–F bond length is 2.18 Å. Al3+ is bonded to four O2- and two equivalent F1- atoms to form AlO4F2 octahedra that share corners with two equivalent AlO4F2 octahedra and corners with four equivalent PO4 tetrahedra. The corner-sharing octahedral tilt angles are 37°. There is two shorter (1.91 Å) and two longer (1.92 Å) Al–O bond length. Both Al–F bond lengths are 1.84 Å. P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with four equivalent AlO4F2 octahedra. The corner-sharing octahedra tilt angles range from 32–49°. There is two shorter (1.55 Å) and two longer (1.56 Å) P–O bond length. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Na1+, one Al3+, and one P5+ atom. In the second O2- site, O2- is bonded in a 3-coordinate geometry to one Na1+, one Al3+, and one P5+ atom. F1- is bonded in a 3-coordinate geometry to one Na1+ and two equivalent Al3+ atoms.