Materials Data on KNd2NbO6 by Materials Project

Abstract

KNd2NbO6 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. K1+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of K–O bond distances ranging from 2.62–2.97 Å. There are two inequivalent Nd3+ sites. In the first 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 2.39–2.61 Å. In the second Nd3+ site, Nd3+ is bonded to seven O2- atoms to form distorted NdO7 hexagonal pyramids that share corners with three equivalent NbO5 trigonal bipyramids, an edgeedge with one NdO7 hexagonal pyramid, and an edgeedge with one NbO5 trigonal bipyramid. There are a spread of Nd–O bond distances ranging from 2.33–2.55 Å. Nb5+ is bonded to five O2- atoms to form distorted NbO5 trigonal bipyramids that share corners with three equivalent NdO7 hexagonal pyramids and an edgeedge with one NdO7 hexagonal pyramid. There are a spread of Nb–O bond distances ranging from 1.86–2.03 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded to three Nd3+ and one Nb5+ atom to form distorted ONd3Nb tetrahedra that share corners with six ONd4 tetrahedra and edges with four ONd3Nb tetrahedra. In the second O2- site, O2- is bonded in a 1-coordinate geometry to two equivalent K1+, two Nd3+, and one Nb5+ atom. In the third O2- site, O2- is bonded to four Nd3+ atoms to form a mixture of corner and edge-sharing ONd4 tetrahedra. In the fourth O2- site, O2- is bonded in a 1-coordinate geometry to three equivalent K1+, one Nd3+, and one Nb5+ atom.