Materials Data on ThU8O18 by Materials Project

Abstract

U8ThO18 is Fluorite-derived structured and crystallizes in the triclinic P-1 space group. The structure is three-dimensional. there are four inequivalent U4+ sites. In the first U4+ site, U4+ is bonded in a body-centered cubic geometry to eight O2- atoms. There are a spread of U–O bond distances ranging from 2.34–2.36 Å. In the second U4+ site, U4+ is bonded in a body-centered cubic geometry to eight O2- atoms. There are a spread of U–O bond distances ranging from 2.34–2.37 Å. In the third U4+ site, U4+ is bonded in a body-centered cubic geometry to eight O2- atoms. There are a spread of U–O bond distances ranging from 2.33–2.37 Å. In the fourth U4+ site, U4+ is bonded in a body-centered cubic geometry to eight O2- atoms. There are a spread of U–O bond distances ranging from 2.34–2.37 Å. Th4+ is bonded in a body-centered cubic geometry to eight O2- atoms. All Th–O bond lengths are 2.40 Å. There are nine inequivalent O2- sites. In the first O2- site, O2- is bonded to four U4+ atoms to form a mixture of edge and corner-sharing OU4 tetrahedra. In the second O2- site, O2- is bonded to four U4+ atoms to form a mixture of edge and corner-sharing OU4 tetrahedra. In the third O2- site, O2- is bonded to three U4+ and one Th4+ atom to form a mixture of edge and corner-sharing OThU3 tetrahedra. In the fourth O2- site, O2- is bonded to four U4+ atoms to form a mixture of edge and corner-sharing OU4 tetrahedra. In the fifth O2- site, O2- is bonded to four U4+ atoms to form a mixture of edge and corner-sharing OU4 tetrahedra. In the sixth O2- site, O2- is bonded to three U4+ and one Th4+ atom to form a mixture of edge and corner-sharing OThU3 tetrahedra. In the seventh O2- site, O2- is bonded to three U4+ and one Th4+ atom to form a mixture of edge and corner-sharing OThU3 tetrahedra. In the eighth O2- site, O2- is bonded to three U4+ and one Th4+ atom to form OThU3 tetrahedra that share corners with sixteen OU4 tetrahedra and edges with six OThU3 tetrahedra. In the ninth O2- site, O2- is bonded to four U4+ atoms to form a mixture of edge and corner-sharing OU4 tetrahedra.