Materials Data on Th2Ta6O19 by Materials Project
Th2Ta6O19 crystallizes in the hexagonal P6_3/mcm space group. The structure is three-dimensional. Th4+ is bonded to six equivalent O2- atoms to form distorted edge-sharing ThO6 octahedra. All Th–O bond lengths are 2.32 Å. Ta5+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Ta–O bond distances ranging from 1.93–2.11 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 150 degrees geometry to two equivalent Ta5+ atoms. In the second O2- site, O2- is bonded in a bent 150 degrees geometry to two equivalent Ta5+ atoms. In the third O2- site, O2- is bonded in a trigonal planar geometry to three equivalent Ta5+ atoms. In the fourth O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Th4+ and one Ta5+ atom.