Materials Data on Ta3O7F by Materials Project

Abstract

Ta3O7F crystallizes in the orthorhombic Cmmm space group. The structure is three-dimensional. there are two inequivalent Ta5+ sites. In the first Ta5+ site, Ta5+ is bonded to four equivalent O2- and two equivalent F1- atoms to form TaO4F2 octahedra that share corners with two equivalent TaO4F2 octahedra, corners with four equivalent TaO7 pentagonal bipyramids, and edges with two equivalent TaO7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 0°. All Ta–O bond lengths are 1.95 Å. Both Ta–F bond lengths are 1.97 Å. In the second Ta5+ site, Ta5+ is bonded to seven O2- atoms to form TaO7 pentagonal bipyramids that share corners with two equivalent TaO4F2 octahedra, corners with three equivalent TaO7 pentagonal bipyramids, an edgeedge with one TaO4F2 octahedra, and edges with two equivalent TaO7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 37°. There are a spread of Ta–O bond distances ranging from 1.92–2.23 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a 3-coordinate geometry to three Ta5+ atoms. In the second O2- site, O2- is bonded in a linear geometry to two equivalent Ta5+ atoms. In the third O2- site, O2- is bonded in a linear geometry to two equivalent Ta5+ atoms. F1- is bonded in a linear geometry to two equivalent Ta5+ atoms.