Materials Data on KH4O2F by Materials Project
KH4O2F crystallizes in the orthorhombic Pmc2_1 space group. The structure is two-dimensional and consists of one KH4O2F sheet oriented in the (0, 1, 0) direction. K1+ is bonded to four O2- and two equivalent F1- atoms to form a mixture of edge and corner-sharing KO4F2 octahedra. The corner-sharing octahedral tilt angles are 69°. There are a spread of K–O bond distances ranging from 2.74–2.82 Å. Both K–F bond lengths are 2.76 Å. There are three inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. In the second H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. In the third H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted water-like geometry to two equivalent K1+ and two equivalent H1+ atoms. In the second O2- site, O2- is bonded in a distorted water-like geometry to two equivalent K1+ and two H1+ atoms. F1- is bonded in a 2-coordinate geometry to two equivalent K1+ atoms.