Materials Data on NaHf2VF11 by Materials Project

Abstract

NaHf2VF11 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. Na1+ is bonded to eight F1- atoms to form distorted NaF8 hexagonal bipyramids that share corners with two equivalent HfF7 pentagonal bipyramids, edges with two equivalent VF6 octahedra, and edges with four equivalent HfF7 pentagonal bipyramids. There are a spread of Na–F bond distances ranging from 2.25–2.76 Å. Hf4+ is bonded to seven F1- atoms to form HfF7 pentagonal bipyramids that share a cornercorner with one NaF8 hexagonal bipyramid, corners with three equivalent VF6 octahedra, a cornercorner with one HfF7 pentagonal bipyramid, edges with two equivalent NaF8 hexagonal bipyramids, and an edgeedge with one HfF7 pentagonal bipyramid. The corner-sharing octahedra tilt angles range from 5–33°. There are a spread of Hf–F bond distances ranging from 1.96–2.15 Å. V2+ is bonded to six F1- atoms to form VF6 octahedra that share corners with six equivalent HfF7 pentagonal bipyramids and edges with two equivalent NaF8 hexagonal bipyramids. There are two shorter (2.12 Å) and four longer (2.13 Å) V–F bond lengths. There are five inequivalent F1- sites. In the first F1- site, F1- is bonded in a distorted bent 150 degrees geometry to one Na1+, one Hf4+, and one V2+ atom. In the second F1- site, F1- is bonded in a linear geometry to two equivalent Hf4+ atoms. In the third F1- site, F1- is bonded in a trigonal planar geometry to one Na1+ and two equivalent Hf4+ atoms. In the fourth F1- site, F1- is bonded in a linear geometry to one Hf4+ and one V2+ atom. In the fifth F1- site, F1- is bonded in a linear geometry to one Na1+ and one Hf4+ atom.