Materials Data on La2Th2O7 by Materials Project

Abstract

Th2La2O7 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 2.39–2.50 Å. La3+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of La–O bond distances ranging from 2.32–2.57 Å. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded to four equivalent La3+ atoms to form OLa4 tetrahedra that share corners with sixteen OLa4 tetrahedra and edges with two equivalent OLa2Th2 tetrahedra. In the second O2- site, O2- is bonded to two equivalent Th4+ and two equivalent La3+ atoms to form OLa2Th2 tetrahedra that share corners with fourteen OTh4 tetrahedra and edges with five OLa2Th2 tetrahedra. In the third O2- site, O2- is bonded to two equivalent Th4+ and two equivalent La3+ atoms to form a mixture of corner and edge-sharing OLa2Th2 tetrahedra. In the fourth O2- site, O2- is bonded to four equivalent Th4+ atoms to form OTh4 tetrahedra that share corners with sixteen OLa2Th2 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 OLa2Th2 tetrahedra.