Materials Data on K2AlH2OF5 by Materials Project
K2AlH2OF5 crystallizes in the orthorhombic Cmcm space group. The structure is three-dimensional. K1+ is bonded in a 7-coordinate geometry to one O2- and seven F1- atoms. The K–O bond length is 2.82 Å. There are a spread of K–F bond distances ranging from 2.73–3.03 Å. Al3+ is bonded to six F1- atoms to form corner-sharing AlF6 octahedra. The corner-sharing octahedral tilt angles are 3°. There are a spread of Al–F bond distances ranging from 1.80–1.90 Å. H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. O2- is bonded in a water-like geometry to two equivalent K1+ and two equivalent H1+ atoms. There are three inequivalent F1- sites. In the first F1- site, F1- is bonded in a linear geometry to two equivalent K1+ and two equivalent Al3+ atoms. In the second F1- site, F1- is bonded in a distorted single-bond geometry to four equivalent K1+ and one Al3+ atom. In the third F1- site, F1- is bonded in a distorted single-bond geometry to two equivalent K1+ and one Al3+ atom.