Materials Data on Hf3N2O3 by Materials Project

Abstract

Hf3N2O3 crystallizes in the orthorhombic Cmc2_1 space group. The structure is three-dimensional. there are three inequivalent Hf4+ sites. In the first Hf4+ site, Hf4+ is bonded to two N3- and four O2- atoms to form a mixture of distorted edge and corner-sharing HfN2O4 octahedra. The corner-sharing octahedra tilt angles range from 28–35°. There are one shorter (2.05 Å) and one longer (2.23 Å) Hf–N bond lengths. There are a spread of Hf–O bond distances ranging from 2.07–2.24 Å. In the second Hf4+ site, Hf4+ is bonded in a 6-coordinate geometry to three N3- and three O2- atoms. There are one shorter (2.04 Å) and two longer (2.13 Å) Hf–N bond lengths. There are a spread of Hf–O bond distances ranging from 2.03–2.52 Å. In the third Hf4+ site, Hf4+ is bonded to two N3- and four O2- atoms to form a mixture of distorted edge and corner-sharing HfN2O4 octahedra. The corner-sharing octahedra tilt angles range from 28–41°. There are one shorter (2.08 Å) and one longer (2.20 Å) Hf–N bond lengths. There are a spread of Hf–O bond distances ranging from 2.06–2.24 Å. There are two inequivalent N3- sites. In the first N3- site, N3- is bonded in a 3-coordinate geometry to three Hf4+ atoms. In the second N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 tetrahedra that share corners with two equivalent NHf4 tetrahedra, a cornercorner with one OHf4 trigonal pyramid, and edges with two equivalent OHf4 trigonal pyramids. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted T-shaped geometry to three Hf4+ atoms. In the second O2- site, O2- is bonded to four Hf4+ atoms to form distorted OHf4 trigonal pyramids that share a cornercorner with one NHf4 tetrahedra, corners with two equivalent OHf4 trigonal pyramids, and edges with two equivalent NHf4 tetrahedra. In the third O2- site, O2- is bonded in a 4-coordinate geometry to four Hf4+ atoms.