Materials Data on Ta4Ag2O11 by Materials Project

Abstract

Ag2Ta4O11 crystallizes in the trigonal R-3c space group. The structure is three-dimensional. 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 corners with two equivalent TaO6 octahedra, corners with two equivalent TaO7 pentagonal bipyramids, and edges with four equivalent TaO7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 44°. There are a spread of Ta–O bond distances ranging from 1.99–2.43 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. Ag1+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Ag–O bond distances ranging from 2.60–2.92 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to two Ta5+ and two equivalent Ag1+ atoms. In the second O2- site, O2- is bonded in a 2-coordinate geometry to three equivalent Ta5+ atoms. In the third O2- site, O2- is bonded in a distorted trigonal planar geometry to three equivalent Ta5+ and one Ag1+ atom.