DOE OSTI2020
Th(SeO3)2 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. Th4+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Th–O bond distances ranging from 2.34–2.61 Å. There are two inequivalent Se4+ sites. In the first Se4+ site, Se4+ is bonded in a trigonal non-coplanar geometry to three O2- atoms. There is two shorter (1.73 Å) and one longer (1.74 Å) Se–O bond length. In the second Se4+ site, Se4+ is bonded in a trigonal non-coplanar geometry to three O2- atoms. There are a spread of Se–O bond distances ranging from 1.71–1.76 Å. There are six inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 150 degrees geometry to one Th4+ and one Se4+ atom. In the second O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Th4+ and one Se4+ atom. In the third O2- site, O2- is bonded in a bent 150 degrees geometry to one Th4+ and one Se4+ atom. In the fourth O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Th4+ and one Se4+ atom. In the fifth O2- site, O2- is bonded in a 2-coordinate geometry to one Th4+ and one Se4+ atom. In the sixth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Th4+ and one Se4+ atom.