DOI: 10.17188/1291739
title: Materials Data on Hf3N2O3 by Materials Project

description: Hf3N2O3 crystallizes in the monoclinic Cm space group. The structure is three-dimensional. there are six 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 28–52°. There are one shorter (2.12 Å) and one longer (2.19 Å) Hf–N bond lengths. There are a spread of Hf–O bond distances ranging from 2.08–2.22 Å. In the second Hf4+ site, Hf4+ is bonded to four N3- and two O2- atoms to form a mixture of distorted edge and corner-sharing HfN4O2 octahedra. The corner-sharing octahedra tilt angles range from 25–52°. There are a spread of Hf–N bond distances ranging from 2.11–2.25 Å. There are one shorter (2.08 Å) and one longer (2.18 Å) Hf–O bond lengths. 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 24–36°. There are one shorter (2.12 Å) and one longer (2.19 Å) Hf–N bond lengths. There are a spread of Hf–O bond distances ranging from 2.07–2.13 Å. In the fourth Hf4+ site, Hf4+ is bonded to three 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 25–40°. There are one shorter (2.11 Å) and two longer (2.16 Å) Hf–N bond lengths. There are a spread of Hf–O bond distances ranging from 2.06–2.29 Å. In the fifth Hf4+ site, Hf4+ is bonded to three N3- and three O2- atoms to form distorted HfN3O3 octahedra that share corners with four HfN2O4 octahedra and edges with six HfN4O2 octahedra. The corner-sharing octahedra tilt angles range from 24–58°. There are two shorter (2.12 Å) and one longer (2.16 Å) Hf–N bond lengths. There are a spread of Hf–O bond distances ranging from 2.06–2.32 Å. In the sixth Hf4+ site, Hf4+ is bonded to two equivalent 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 24–58°. Both Hf–N bond lengths are 2.13 Å. There are a spread of Hf–O bond distances ranging from 2.00–2.27 Å. There are four inequivalent N3- sites. In the first N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 tetrahedra that share corners with two equivalent NHf4 tetrahedra, corners with two NHf4 trigonal pyramids, and edges with two equivalent OHf4 trigonal pyramids. In the second N3- site, N3- is bonded to four Hf4+ atoms to form a mixture of distorted edge and corner-sharing NHf4 trigonal pyramids. In the third N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share a cornercorner with one NHf4 tetrahedra, corners with three NHf4 trigonal pyramids, edges with two equivalent NHf4 trigonal pyramids, and edges with two equivalent OHf4 trigonal pyramids. In the fourth N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 trigonal pyramids that share a cornercorner with one OHf4 trigonal pyramid, corners with two equivalent NHf4 trigonal pyramids, and edges with four NHf4 trigonal pyramids. There are six 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 in a distorted T-shaped geometry to three Hf4+ atoms. In the third O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to three Hf4+ atoms. In the fourth O2- site, O2- is bonded in a distorted T-shaped geometry to three Hf4+ atoms. In the fifth O2- site, O2- is bonded to four Hf4+ atoms to form distorted OHf4 trigonal pyramids that share a cornercorner with one NHf4 trigonal pyramid, corners with two equivalent OHf4 trigonal pyramids, edges with two equivalent NHf4 tetrahedra, and edges with two equivalent NHf4 trigonal pyramids. In the sixth O2- site, O2- is bonded in a 4-coordinate geometry to four Hf4+ atoms.