Materials Data on K2AlSO4F3 by Materials Project
K2AlSO4F3 crystallizes in the orthorhombic Pbcn space group. The structure is three-dimensional. K1+ is bonded in a 9-coordinate geometry to five O2- and four F1- atoms. There are a spread of K–O bond distances ranging from 2.71–3.34 Å. There are a spread of K–F bond distances ranging from 2.75–3.01 Å. Al3+ is bonded to two equivalent O2- and four F1- atoms to form AlO2F4 octahedra that share corners with two equivalent AlO2F4 octahedra and corners with two equivalent SO4 tetrahedra. The corner-sharing octahedral tilt angles are 44°. Both Al–O bond lengths are 1.93 Å. There is two shorter (1.78 Å) and two longer (1.88 Å) Al–F bond length. S6+ is bonded to four O2- atoms to form SO4 tetrahedra that share corners with two equivalent AlO2F4 octahedra. The corner-sharing octahedral tilt angles are 49°. There is two shorter (1.46 Å) and two longer (1.52 Å) S–O bond length. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted single-bond geometry to three equivalent K1+ and one S6+ atom. In the second O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent K1+, one Al3+, and one S6+ atom. There are two inequivalent F1- sites. In the first F1- site, F1- is bonded in a distorted single-bond geometry to three equivalent K1+ and one Al3+ atom. In the second F1- site, F1- is bonded in a 2-coordinate geometry to two equivalent K1+ and two equivalent Al3+ atoms.