Materials Data on TbTa3O9 by Materials Project

Abstract

TbTa3O9 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. Tb3+ is bonded to twelve O2- atoms to form TbO12 cuboctahedra that share corners with three equivalent TbO12 cuboctahedra, faces with two equivalent TbO12 cuboctahedra, and faces with eight TaO6 octahedra. There are a spread of Tb–O bond distances ranging from 2.52–2.89 Å. There are three inequivalent Ta5+ sites. In the first Ta5+ site, Ta5+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with six TaO6 octahedra and faces with three equivalent TbO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–18°. There are a spread of Ta–O bond distances ranging from 1.93–2.05 Å. 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 TbO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–15°. There is two shorter (1.97 Å) and four longer (1.99 Å) Ta–O bond length. In the third Ta5+ site, Ta5+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with six TaO6 octahedra and faces with three equivalent TbO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 3–18°. There are a spread of Ta–O bond distances ranging from 1.91–2.08 Å. There are seven inequivalent O2- sites. In the first O2- site, O2- is bonded in a linear geometry to two equivalent Tb3+ and two equivalent Ta5+ atoms. In the second O2- site, O2- is bonded in a 3-coordinate geometry to one Tb3+ and two Ta5+ atoms. In the third O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Tb3+ and two Ta5+ atoms. In the fourth O2- site, O2- is bonded in a 2-coordinate geometry to three equivalent Tb3+ and two Ta5+ atoms. In the fifth O2- site, O2- is bonded in a linear geometry to two equivalent Ta5+ atoms. In the sixth O2- site, O2- is bonded in a linear geometry to two Ta5+ atoms. In the seventh O2- site, O2- is bonded in a 2-coordinate geometry to one Tb3+ and two Ta5+ atoms.