DOE OSTI2020
Th(Se2O5)2 crystallizes in the orthorhombic Pbca 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 2.37–2.55 Å. There are four inequivalent Se4+ sites. In the first 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 1.69–1.86 Å. In the second Se4+ site, Se4+ is bonded in a distorted trigonal non-coplanar geometry to three O2- atoms. There are a spread of Se–O bond distances ranging from 1.69–1.89 Å. In the third Se4+ site, Se4+ is bonded in a trigonal non-coplanar geometry to three O2- atoms. There is two shorter (1.70 Å) and one longer (1.86 Å) Se–O bond length. In the fourth 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 1.69–1.83 Å. There are ten inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 120 degrees geometry to two Se4+ atoms. In the second O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Th4+ and one Se4+ atom. In the third O2- site, O2- is bonded in a 2-coordinate geometry to one Th4+ and one Se4+ atom. In the fourth O2- site, O2- is bonded in a bent 120 degrees geometry to two Se4+ atoms. In the fifth O2- site, O2- is bonded in a linear 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. In the seventh O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Th4+ and one Se4+ atom. In the eighth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Th4+ and one Se4+ atom. In the ninth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Th4+ and one Se4+ atom. In the tenth O2- site, O2- is bonded in a bent 150 degrees geometry to one Th4+ and one Se4+ atom.