Materials Data on K2HfO6 by Materials Project

K2HfO6 crystallizes in the orthorhombic Cmme space group. The structure is two-dimensional and consists of two K2HfO6 sheets oriented in the (0, 1, 0) direction. there are two inequivalent K sites. In the first K site, K is bonded in a 10-coordinate geometry to ten O atoms. There are a spread of K–O bond distances ranging from 2.75–3.09 Å. In the second K site, K is bonded in a 10-coordinate geometry to ten O atoms. There are a spread of K–O bond distances ranging from 2.76–3.14 Å. There are two inequivalent Hf sites. In the first Hf site, Hf is bonded to six O atoms to form corner-sharing HfO6 octahedra. The corner-sharing octahedra tilt angles range from 0–1°. There are two shorter (2.06 Å) and four longer (2.08 Å) Hf–O bond lengths. In the second Hf site, Hf is bonded to six O atoms to form corner-sharing HfO6 octahedra. The corner-sharing octahedra tilt angles range from 0–1°. There are a spread of Hf–O bond distances ranging from 2.01–2.09 Å. There are five inequivalent O sites. In the first O site, O is bonded in a linear geometry to four K and two Hf atoms. In the second O site, O is bonded in a linear geometry to four K and two Hf atoms. In the third O site, O is bonded in a distorted single-bond geometry to four K and one Hf atom. In the fourth O site, O is bonded in a distorted single-bond geometry to four K and one Hf atom. In the fifth O site, O is bonded in a water-like geometry to two K atoms.