Materials Data on Eu3NbO7 by Materials Project

Abstract

Eu3NbO7 crystallizes in the orthorhombic P2_12_12_1 space group. The structure is three-dimensional. there are three inequivalent Eu3+ sites. In the first Eu3+ site, Eu3+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Eu–O bond distances ranging from 2.37–2.73 Å. In the second Eu3+ site, Eu3+ is bonded to seven O2- atoms to form distorted EuO7 pentagonal bipyramids that share corners with two equivalent NbO6 octahedra, corners with three EuO7 pentagonal bipyramids, edges with two equivalent NbO6 octahedra, and edges with two equivalent EuO7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 40–44°. There are a spread of Eu–O bond distances ranging from 2.19–2.67 Å. In the third Eu3+ site, Eu3+ is bonded to seven O2- atoms to form distorted EuO7 pentagonal bipyramids that share corners with two equivalent NbO6 octahedra, corners with three EuO7 pentagonal bipyramids, edges with two equivalent NbO6 octahedra, and edges with two equivalent EuO7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 33–43°. There are a spread of Eu–O bond distances ranging from 2.30–2.72 Å. Nb5+ is bonded to six O2- atoms to form NbO6 octahedra that share corners with two equivalent NbO6 octahedra, corners with four EuO7 pentagonal bipyramids, and edges with four EuO7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 33°. There are a spread of Nb–O bond distances ranging from 1.93–2.08 Å. There are seven inequivalent O2- sites. In the first O2- site, O2- is bonded to four Eu3+ atoms to form a mixture of corner and edge-sharing OEu4 tetrahedra. In the second O2- site, O2- is bonded to four Eu3+ atoms to form a mixture of corner and edge-sharing OEu4 tetrahedra. In the third O2- site, O2- is bonded in a 2-coordinate geometry to two Eu3+ and two equivalent Nb5+ atoms. In the fourth O2- site, O2- is bonded in a 3-coordinate geometry to two Eu3+ and one Nb5+ atom. In the fifth O2- site, O2- is bonded to three Eu3+ and one Nb5+ atom to form a mixture of distorted corner and edge-sharing OEu3Nb tetrahedra. In the sixth O2- site, O2- is bonded in a 4-coordinate geometry to three Eu3+ and one Nb5+ atom. In the seventh O2- site, O2- is bonded to three Eu3+ and one Nb5+ atom to form a mixture of distorted corner and edge-sharing OEu3Nb tetrahedra.