Materials Data on KH4F5 by Materials Project
KH4F5 crystallizes in the tetragonal I4_1/a space group. The structure is three-dimensional. K1+ is bonded to eight equivalent F1- atoms to form distorted edge-sharing KF8 hexagonal bipyramids. There are four shorter (2.70 Å) and four longer (3.12 Å) K–F bond lengths. H1+ is bonded in a linear geometry to two F1- atoms. There is one shorter (0.98 Å) and one longer (1.49 Å) H–F bond length. There are two inequivalent F1- sites. In the first F1- site, F1- is bonded in a rectangular see-saw-like geometry to four equivalent H1+ atoms. In the second F1- site, F1- is bonded in a distorted single-bond geometry to two equivalent K1+ and one H1+ atom.