Materials Data on Hf2N2O by Materials Project

Abstract

Hf2ON2 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. there are two inequivalent Hf4+ sites. In the first Hf4+ site, Hf4+ is bonded in a 7-coordinate geometry to five N3- and two equivalent O2- atoms. There are a spread of Hf–N bond distances ranging from 2.07–2.50 Å. There are one shorter (2.09 Å) and one longer (2.10 Å) Hf–O bond lengths. In the second Hf4+ site, Hf4+ is bonded in a 7-coordinate geometry to five N3- and two equivalent O2- atoms. There are a spread of Hf–N bond distances ranging from 2.06–2.49 Å. There are one shorter (2.09 Å) and one longer (2.47 Å) Hf–O bond lengths. There are two inequivalent N3- sites. In the first N3- site, N3- is bonded to six Hf4+ atoms to form NHf6 octahedra that share corners with six equivalent NHf4 tetrahedra, edges with six equivalent NHf6 octahedra, and edges with three equivalent NHf4 tetrahedra. In the second N3- site, N3- is bonded to four Hf4+ atoms to form distorted NHf4 tetrahedra that share corners with six equivalent NHf6 octahedra, corners with two equivalent NHf4 tetrahedra, edges with three equivalent NHf6 octahedra, and an edgeedge with one NHf4 tetrahedra. The corner-sharing octahedra tilt angles range from 10–57°. O2- is bonded in a 3-coordinate geometry to four Hf4+ atoms.