Materials Data on Ce2Nd2O7 by Materials Project

Abstract

Nd2Ce2O7 crystallizes in the orthorhombic Pmma space group. The structure is three-dimensional. there are two inequivalent Nd3+ sites. In the first 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 68°. There are two shorter (2.40 Å) and four longer (2.41 Å) Nd–O bond lengths. In the second Nd3+ site, Nd3+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Nd–O bond distances ranging from 2.28–2.44 Å. There are two inequivalent Ce4+ sites. In the first Ce4+ site, Ce4+ is bonded in a body-centered cubic geometry to eight O2- atoms. There are a spread of Ce–O bond distances ranging from 2.30–2.70 Å. In the second Ce4+ site, Ce4+ is bonded in a body-centered cubic geometry to eight O2- atoms. There are a spread of Ce–O bond distances ranging from 2.33–2.50 Å. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded to two equivalent Nd3+ and two equivalent Ce4+ atoms to form OCe2Nd2 tetrahedra that share corners with fourteen OCe2Nd2 tetrahedra and edges with five OCeNd3 tetrahedra. In the second O2- site, O2- is bonded to three Nd3+ and one Ce4+ atom to form a mixture of distorted edge and corner-sharing OCeNd3 tetrahedra. In the third O2- site, O2- is bonded to four Ce4+ atoms to form a mixture of edge and corner-sharing OCe4 tetrahedra. In the fourth O2- site, O2- is bonded to one Nd3+ and three Ce4+ atoms to form OCe3Nd tetrahedra that share corners with fourteen OCe2Nd2 tetrahedra and edges with six OCeNd3 tetrahedra. In the fifth O2- site, O2- is bonded to two equivalent Nd3+ and two equivalent Ce4+ atoms to form OCe2Nd2 tetrahedra that share corners with fourteen OCeNd3 tetrahedra and edges with five OCe4 tetrahedra.