Materials Data on Gd3NbO7 by Materials Project

Abstract

Gd3NbO7 crystallizes in the orthorhombic Cmcm space group. The structure is three-dimensional. there are two inequivalent Gd3+ sites. In the first Gd3+ site, Gd3+ is bonded in a body-centered cubic geometry to eight O2- atoms. There are a spread of Gd–O bond distances ranging from 2.37–2.66 Å. In the second Gd3+ site, Gd3+ is bonded to seven O2- atoms to form distorted GdO7 pentagonal bipyramids that share corners with two equivalent NbO6 octahedra, a cornercorner with one GdO7 pentagonal bipyramid, edges with two equivalent NbO6 octahedra, and edges with three equivalent GdO7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 46°. There are a spread of Gd–O bond distances ranging from 2.25–2.50 Å. Nb5+ is bonded to six O2- atoms to form NbO6 octahedra that share corners with two equivalent NbO6 octahedra, corners with four equivalent GdO7 pentagonal bipyramids, and edges with four equivalent GdO7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 40°. There are four shorter (2.00 Å) and two longer (2.03 Å) Nb–O bond lengths. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to three Gd3+ and one Nb5+ atom. In the second O2- site, O2- is bonded to four Gd3+ atoms to form a mixture of edge and corner-sharing OGd4 tetrahedra. In the third O2- site, O2- is bonded to four Gd3+ atoms to form a mixture of edge and corner-sharing OGd4 tetrahedra. In the fourth O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Gd3+ and two equivalent Nb5+ atoms.