Materials Data on Ce2Th2O7 by Materials Project
Th2Ce2O7 crystallizes in the tetragonal P-4m2 space group. The structure is three-dimensional. Th4+ is bonded in a body-centered cubic geometry to eight O2- atoms. There are a spread of Th–O bond distances ranging from 2.38–2.48 Å. Ce3+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Ce–O bond distances ranging from 2.31–2.47 Å. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded to four equivalent Ce3+ atoms to form OCe4 tetrahedra that share corners with sixteen OCe4 tetrahedra and edges with two equivalent OCe2Th2 tetrahedra. In the second O2- site, O2- is bonded to two equivalent Th4+ and two equivalent Ce3+ atoms to form a mixture of edge and corner-sharing OCe2Th2 tetrahedra. In the third O2- site, O2- is bonded to two equivalent Th4+ and two equivalent Ce3+ atoms to form OCe2Th2 tetrahedra that share corners with twelve OTh4 tetrahedra and edges with six OCe4 tetrahedra. In the fourth O2- site, O2- is bonded to four equivalent Th4+ atoms to form OTh4 tetrahedra that share corners with sixteen OCe2Th2 tetrahedra and edges with six OTh4 tetrahedra. In the fifth O2- site, O2- is bonded to four equivalent Th4+ atoms to form OTh4 tetrahedra that share corners with sixteen OTh4 tetrahedra and edges with six OCe2Th2 tetrahedra.