Materials Data on Nd2ScNbO7 by Materials Project

Abstract

Nd2ScNbO7 crystallizes in the orthorhombic Imma space group. The structure is three-dimensional. there are two inequivalent Nd3+ sites. In the first Nd3+ site, Nd3+ is bonded to eight O2- atoms to form distorted NdO8 hexagonal bipyramids that share edges with two equivalent NdO8 hexagonal bipyramids, edges with two equivalent ScO6 octahedra, and edges with four equivalent NbO6 octahedra. There are a spread of Nd–O bond distances ranging from 2.28–2.67 Å. In the second Nd3+ site, Nd3+ is bonded in a body-centered cubic geometry to eight O2- atoms. There are a spread of Nd–O bond distances ranging from 2.33–2.63 Å. Sc3+ is bonded to six O2- atoms to form ScO6 octahedra that share corners with two equivalent ScO6 octahedra, corners with four equivalent NbO6 octahedra, and edges with two equivalent NdO8 hexagonal bipyramids. The corner-sharing octahedra tilt angles range from 49–56°. There are two shorter (2.12 Å) and four longer (2.14 Å) Sc–O bond lengths. Nb5+ is bonded to six O2- atoms to form NbO6 octahedra that share corners with two equivalent NbO6 octahedra, corners with four equivalent ScO6 octahedra, and edges with four equivalent NdO8 hexagonal bipyramids. The corner-sharing octahedra tilt angles range from 43–49°. There are four shorter (2.00 Å) and two longer (2.04 Å) Nb–O bond lengths. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded to four Nd3+ atoms to form ONd4 tetrahedra that share corners with six ONd4 tetrahedra and an edgeedge with one ONd2Sc2 tetrahedra. In the second O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Nd3+ and two equivalent Nb5+ atoms. In the third O2- site, O2- is bonded to two equivalent Nd3+ and two equivalent Sc3+ atoms to form a mixture of distorted edge and corner-sharing ONd2Sc2 tetrahedra. In the fourth O2- site, O2- is bonded in a 4-coordinate geometry to two Nd3+, one Sc3+, and one Nb5+ atom.