Materials Data on Gd3NbO7 by Materials Project

Abstract

Gd3NbO7 crystallizes in the orthorhombic C222_1 space group. The structure is three-dimensional. there are two inequivalent Gd3+ sites. In the first 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 octahedra tilt angles range from 42–49°. There are a spread of Gd–O bond distances ranging from 2.25–2.51 Å. In the second Gd3+ site, Gd3+ is bonded in a distorted body-centered cubic geometry to eight O2- atoms. There are a spread of Gd–O bond distances ranging from 2.36–2.90 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 41°. There are a spread of Nb–O bond distances ranging from 1.97–2.05 Å. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Gd3+ and two equivalent Nb5+ atoms. 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 in a 3-coordinate geometry to three Gd3+ and one Nb5+ atom. In the fourth O2- site, O2- is bonded to four Gd3+ atoms to form a mixture of edge and corner-sharing OGd4 tetrahedra. In the fifth O2- site, O2- is bonded to three Gd3+ and one Nb5+ atom to form a mixture of distorted edge and corner-sharing OGd3Nb tetrahedra.