Materials Data on Hf6PbO18 by Materials Project

Abstract

Hf6PbO18 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. there are two inequivalent Hf sites. In the first Hf site, Hf is bonded to six O atoms to form HfO6 octahedra that share corners with six HfO6 octahedra and a faceface with one PbO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–10°. There are a spread of Hf–O bond distances ranging from 2.04–2.11 Å. In the second Hf site, Hf is bonded to six O atoms to form HfO6 octahedra that share corners with six HfO6 octahedra and faces with two equivalent PbO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 6–8°. There are two shorter (2.07 Å) and four longer (2.08 Å) Hf–O bond lengths. Pb is bonded to twelve O atoms to form PbO12 cuboctahedra that share faces with eight HfO6 octahedra. There are a spread of Pb–O bond distances ranging from 2.78–2.83 Å. There are seven inequivalent O sites. In the first O site, O is bonded in a linear geometry to two equivalent Hf atoms. In the second O site, O is bonded in a linear geometry to two Hf and one Pb atom. In the third O site, O is bonded in a distorted linear geometry to two equivalent Hf and one Pb atom. In the fourth O site, O is bonded in a linear geometry to two equivalent Hf and one Pb atom. In the fifth O site, O is bonded in a linear geometry to two equivalent Hf atoms. In the sixth O site, O is bonded in a linear geometry to two equivalent Hf atoms. In the seventh O site, O is bonded in a linear geometry to two Hf and one Pb atom.