DOE OSTI2020
Nd2O3 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. there are three inequivalent Nd3+ sites. In the first Nd3+ site, Nd3+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Nd–O bond distances ranging from 2.35–2.77 Å. In the second Nd3+ site, Nd3+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Nd–O bond distances ranging from 2.35–2.83 Å. In the third Nd3+ site, Nd3+ is bonded to six O2- atoms to form a mixture of distorted edge and corner-sharing NdO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are a spread of Nd–O bond distances ranging from 2.31–2.62 Å. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded to four Nd3+ atoms to form ONd4 tetrahedra that share corners with two equivalent ONd6 octahedra, corners with two equivalent ONd5 square pyramids, corners with four ONd4 tetrahedra, corners with six equivalent ONd4 trigonal pyramids, an edgeedge with one ONd6 octahedra, edges with two equivalent ONd5 square pyramids, and an edgeedge with one ONd4 tetrahedra. The corner-sharing octahedral tilt angles are 15°. In the second O2- site, O2- is bonded to four Nd3+ atoms to form distorted ONd4 trigonal pyramids that share a cornercorner with one ONd6 octahedra, corners with two equivalent ONd5 square pyramids, corners with nine ONd4 tetrahedra, corners with two equivalent ONd4 trigonal pyramids, edges with three equivalent ONd5 square pyramids, and edges with two equivalent ONd4 trigonal pyramids. The corner-sharing octahedral tilt angles are 35°. In the third O2- site, O2- is bonded to five Nd3+ atoms to form distorted ONd5 square pyramids that share corners with seven ONd4 tetrahedra, corners with two equivalent ONd4 trigonal pyramids, edges with two equivalent ONd6 octahedra, edges with two equivalent ONd5 square pyramids, edges with three ONd4 tetrahedra, and edges with three equivalent ONd4 trigonal pyramids. In the fourth O2- site, O2- is bonded to six Nd3+ atoms to form ONd6 octahedra that share corners with six ONd4 tetrahedra, corners with two equivalent ONd4 trigonal pyramids, edges with two equivalent ONd6 octahedra, edges with four equivalent ONd5 square pyramids, and edges with six ONd4 tetrahedra. In the fifth O2- site, O2- is bonded to four Nd3+ atoms to form ONd4 tetrahedra that share a cornercorner with one ONd6 octahedra, corners with five equivalent ONd5 square pyramids, corners with four ONd4 tetrahedra, corners with three equivalent ONd4 trigonal pyramids, edges with two equivalent ONd6 octahedra, an edgeedge with one ONd5 square pyramid, and edges with two equivalent ONd4 tetrahedra. The corner-sharing octahedral tilt angles are 51°.