Materials Data on Li3Ta7O19 by Materials Project

Abstract

Li3Ta7O19 crystallizes in the hexagonal P6_3/m space group. The structure is three-dimensional. Li1+ is bonded in a linear geometry to two equivalent O2- atoms. Both Li–O bond lengths are 1.87 Å. There are two inequivalent Ta5+ sites. In the first Ta5+ site, Ta5+ is bonded to seven O2- atoms to form distorted TaO7 pentagonal bipyramids that share a cornercorner with one TaO6 octahedra, corners with three equivalent TaO7 pentagonal bipyramids, and edges with four equivalent TaO7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 47°. There are a spread of Ta–O bond distances ranging from 1.93–2.47 Å. In the second Ta5+ site, Ta5+ is bonded to six equivalent O2- atoms to form corner-sharing TaO6 octahedra. All Ta–O bond lengths are 2.01 Å. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded in a trigonal planar geometry to three equivalent Ta5+ atoms. In the second O2- site, O2- is bonded in a 3-coordinate geometry to one Li1+ and two Ta5+ atoms. In the third O2- site, O2- is bonded in a linear geometry to two equivalent Ta5+ atoms. In the fourth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to three equivalent Ta5+ atoms. In the fifth O2- site, O2- is bonded in a trigonal planar geometry to three equivalent Ta5+ atoms.