Materials Data on Hf3N2O3 by Materials Project

Abstract

Hf3N2O3 crystallizes in the orthorhombic Cmcm space group. The structure is three-dimensional. there are two inequivalent Hf4+ sites. In the first Hf4+ site, Hf4+ is bonded to two equivalent N3- and four O2- atoms to form distorted HfN2O4 octahedra that share corners with four HfN2O4 octahedra and edges with six equivalent HfN3O3 octahedra. The corner-sharing octahedra tilt angles range from 25–35°. Both Hf–N bond lengths are 2.14 Å. There are two shorter (2.11 Å) and two longer (2.12 Å) Hf–O bond lengths. In the second Hf4+ site, Hf4+ is bonded to three equivalent N3- and three O2- atoms to form a mixture of distorted edge and corner-sharing HfN3O3 octahedra. The corner-sharing octahedra tilt angles range from 25–56°. There are two shorter (2.12 Å) and one longer (2.18 Å) Hf–N bond lengths. There are a spread of Hf–O bond distances ranging from 2.07–2.32 Å. N3- is bonded to four Hf4+ atoms to form a mixture of distorted edge and corner-sharing NHf4 trigonal pyramids. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to four Hf4+ atoms. In the second O2- site, O2- is bonded in a distorted T-shaped geometry to three Hf4+ atoms.