Materials Data on Ta6TiTl2O18 by Materials Project

Abstract

TiTa6Tl2O18 crystallizes in the monoclinic C2 space group. The structure is three-dimensional. Ti4+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with six TaO6 octahedra. The corner-sharing octahedra tilt angles range from 34–35°. There is four shorter (1.97 Å) and two longer (1.98 Å) Ti–O bond length. There are three inequivalent Ta5+ sites. In the first Ta5+ site, Ta5+ is bonded to six O2- atoms to form distorted TaO6 octahedra that share a cornercorner with one TiO6 octahedra, corners with four TaO6 octahedra, and edges with two TaO6 octahedra. The corner-sharing octahedra tilt angles range from 26–49°. There are a spread of Ta–O bond distances ranging from 1.86–2.13 Å. In the second Ta5+ site, Ta5+ is bonded to six O2- atoms to form distorted TaO6 octahedra that share a cornercorner with one TiO6 octahedra, corners with four TaO6 octahedra, and edges with two TaO6 octahedra. The corner-sharing octahedra tilt angles range from 25–50°. There are a spread of Ta–O bond distances ranging from 1.86–2.14 Å. In the third Ta5+ site, Ta5+ is bonded to six O2- atoms to form distorted TaO6 octahedra that share a cornercorner with one TiO6 octahedra, corners with four TaO6 octahedra, and edges with two TaO6 octahedra. The corner-sharing octahedra tilt angles range from 25–50°. There are a spread of Ta–O bond distances ranging from 1.86–2.13 Å. Tl1+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Tl–O bond distances ranging from 2.79–3.37 Å. There are nine inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 150 degrees geometry to one Ti4+ and one Ta5+ atom. In the second O2- site, O2- is bonded in a bent 150 degrees geometry to two Ta5+ and one Tl1+ atom. In the third O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two Ta5+ and one Tl1+ atom. In the fourth O2- site, O2- is bonded in a bent 150 degrees geometry to two Ta5+ and one Tl1+ atom. In the fifth O2- site, O2- is bonded in a 3-coordinate geometry to three Ta5+ and one Tl1+ atom. In the sixth O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to three Ta5+ and one Tl1+ atom. In the seventh O2- site, O2- is bonded in a 3-coordinate geometry to three Ta5+ and one Tl1+ atom. In the eighth O2- site, O2- is bonded in a bent 150 degrees geometry to one Ti4+ and one Ta5+ atom. In the ninth O2- site, O2- is bonded in a bent 150 degrees geometry to one Ti4+ and one Ta5+ atom.