Materials Data on Nd2Th3O9 by Materials Project
Th3Nd2O9 crystallizes in the tetragonal I-4m2 space group. The structure is three-dimensional. there are two inequivalent Th4+ sites. In the first Th4+ site, Th4+ is bonded in a body-centered cubic geometry to eight O2- atoms. There are a spread of Th–O bond distances ranging from 2.35–2.53 Å. In the second Th4+ site, Th4+ is bonded in a body-centered cubic geometry to eight O2- atoms. There are four shorter (2.39 Å) and four longer (2.49 Å) Th–O bond lengths. Nd3+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Nd–O bond distances ranging from 2.27–2.55 Å. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded to two equivalent Th4+ and two equivalent Nd3+ atoms to form a mixture of edge and corner-sharing ONd2Th2 tetrahedra. In the second O2- site, O2- is bonded to four Th4+ atoms to form a mixture of edge and corner-sharing OTh4 tetrahedra. In the third O2- site, O2- is bonded to two equivalent Th4+ and two equivalent Nd3+ atoms to form ONd2Th2 tetrahedra that share corners with fourteen OTh4 tetrahedra and edges with five ONd2Th2 tetrahedra. In the fourth O2- site, O2- is bonded to four equivalent Nd3+ atoms to form a mixture of edge and corner-sharing ONd4 tetrahedra. In the fifth O2- site, O2- is bonded to four Th4+ atoms to form OTh4 tetrahedra that share corners with sixteen OTh4 tetrahedra and edges with six ONd2Th2 tetrahedra.