Materials Data on ErTa5Ag2O15 by Materials Project

Abstract

ErTa5Ag2O15 crystallizes in the tetragonal P4/mbm space group. The structure is three-dimensional. Er3+ is bonded to twelve O2- atoms to form ErO12 cuboctahedra that share faces with two equivalent ErO12 cuboctahedra and faces with eight equivalent TaO6 octahedra. There are four shorter (2.57 Å) and eight longer (2.65 Å) Er–O bond lengths. There are two inequivalent Ta5+ sites. In the first Ta5+ site, Ta5+ is bonded to six O2- atoms to form corner-sharing TaO6 octahedra. The corner-sharing octahedra tilt angles range from 0–32°. There is two shorter (1.96 Å) and four longer (2.00 Å) Ta–O bond length. In the second Ta5+ site, Ta5+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with six TaO6 octahedra and faces with two equivalent ErO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 13–42°. There are a spread of Ta–O bond distances ranging from 1.92–2.05 Å. Ag1+ is bonded in a 2-coordinate geometry to nine O2- atoms. There are a spread of Ag–O bond distances ranging from 2.69–3.13 Å. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two Ta5+ and two equivalent Ag1+ atoms. In the second O2- site, O2- is bonded in a 2-coordinate geometry to one Er3+, two equivalent Ta5+, and one Ag1+ atom. In the third O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Ta5+ and two equivalent Ag1+ atoms. In the fourth O2- site, O2- is bonded in a linear geometry to two equivalent Ta5+ and two equivalent Ag1+ atoms. In the fifth O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent Er3+ and two equivalent Ta5+ atoms.