Materials Data on Th2Ta2O9 by Materials Project
Ta2Th2O9 crystallizes in the orthorhombic C222_1 space group. The structure is three-dimensional. there are three inequivalent Th4+ sites. In the first Th4+ site, Th4+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Th–O bond distances ranging from 2.33–2.82 Å. In the second Th4+ site, Th4+ is bonded in a 10-coordinate geometry to ten O2- atoms. There are a spread of Th–O bond distances ranging from 2.37–2.87 Å. In the third Th4+ site, Th4+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Th–O bond distances ranging from 2.24–2.83 Å. There are three 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 25–62°. There are a spread of Ta–O bond distances ranging from 1.92–2.16 Å. In the second Ta5+ site, Ta5+ is bonded to six O2- atoms to form corner-sharing TaO6 octahedra. The corner-sharing octahedra tilt angles range from 28–47°. There are four shorter (1.98 Å) and two longer (2.04 Å) Ta–O bond lengths. In the third Ta5+ site, Ta5+ is bonded to six O2- atoms to form corner-sharing TaO6 octahedra. The corner-sharing octahedra tilt angles range from 28–62°. There are a spread of Ta–O bond distances ranging from 1.93–2.26 Å. There are eleven inequivalent O2- sites. In the first O2- site, O2- is bonded in a trigonal planar geometry to two equivalent Th4+ and one Ta5+ atom. In the second O2- site, O2- is bonded in a trigonal planar geometry to three Ta5+ atoms. In the third O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent Th4+ and two equivalent Ta5+ atoms. In the fourth O2- site, O2- is bonded in a bent 150 degrees geometry to one Th4+ and two equivalent Ta5+ atoms. In the fifth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Th4+ and two Ta5+ atoms. In the sixth O2- site, O2- is bonded in a 2-coordinate geometry to two Th4+ and two Ta5+ atoms. In the seventh O2- site, O2- is bonded in a distorted trigonal planar geometry to three Th4+ atoms. In the eighth O2- site, O2- is bonded in a 1-coordinate geometry to three Th4+ and one Ta5+ atom. In the ninth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Th4+ and one Ta5+ atom. In the tenth O2- site, O2- is bonded in a 3-coordinate geometry to two Th4+ and one Ta5+ atom. In the eleventh O2- site, O2- is bonded in a 1-coordinate geometry to three Th4+ and one Ta5+ atom.