Materials Data on Nd3TaO7 by Materials Project

Abstract

Nd3TaO7 crystallizes in the orthorhombic Cmcm space group. The structure is three-dimensional. 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 four shorter (2.42 Å) and four longer (2.76 Å) Nd–O bond lengths. In the second Nd3+ site, Nd3+ is bonded to seven O2- atoms to form distorted NdO7 pentagonal bipyramids that share corners with two equivalent TaO6 octahedra, corners with three equivalent NdO7 pentagonal bipyramids, edges with two equivalent TaO6 octahedra, and edges with two equivalent NdO7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 39°. There are a spread of Nd–O bond distances ranging from 2.31–2.72 Å. Ta5+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with two equivalent TaO6 octahedra, corners with four equivalent NdO7 pentagonal bipyramids, and edges with four equivalent NdO7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 29°. All Ta–O bond lengths are 2.00 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two equivalent Nd3+ and two equivalent Ta5+ atoms. In the second O2- site, O2- is bonded in a 4-coordinate geometry to three Nd3+ and one Ta5+ atom. In the third O2- site, O2- is bonded to four Nd3+ atoms to form a mixture of corner and edge-sharing ONd4 tetrahedra.