Materials Data on HfO2 by Materials Project

Abstract

HfO2 is Baddeleyite-like structured and crystallizes in the orthorhombic P2_12_12 space group. The structure is three-dimensional. Hf4+ is bonded to seven O2- atoms to form a mixture of distorted corner, edge, and face-sharing HfO7 pentagonal bipyramids. There are a spread of Hf–O bond distances ranging from 2.01–2.28 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a 3-coordinate geometry to three equivalent Hf4+ atoms. In the second O2- site, O2- is bonded to four equivalent Hf4+ atoms to form a mixture of distorted corner and edge-sharing OHf4 trigonal pyramids. In the third O2- site, O2- is bonded to four equivalent Hf4+ atoms to form a mixture of corner and edge-sharing OHf4 tetrahedra.