Materials Data on KH8O4F by Materials Project
(K(H2O)4)2F2 crystallizes in the monoclinic P2_1/c space group. The structure is two-dimensional and consists of four hydrofluoric acid molecules and one K(H2O)4 sheet oriented in the (0, 0, 1) direction. In the K(H2O)4 sheet, K1+ is bonded to six O2- atoms to form a mixture of edge and corner-sharing KO6 octahedra. The corner-sharing octahedral tilt angles are 69°. There are a spread of K–O bond distances ranging from 2.76–2.82 Å. There are eight 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. In the fourth 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 fifth 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 sixth 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 seventh H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. In the eighth 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 four inequivalent O2- sites. In the first O2- site, O2- is bonded in a water-like geometry to two equivalent K1+ and two H1+ atoms. In the second O2- site, O2- is bonded in a water-like geometry to one K1+ and two H1+ atoms. In the third O2- site, O2- is bonded in a distorted water-like geometry to two equivalent K1+ and two H1+ atoms. In the fourth O2- site, O2- is bonded in a water-like geometry to one K1+ and two H1+ atoms.