Materials Data on Nd3TaO7 by Materials Project
Nd3TaO7 crystallizes in the orthorhombic C222_1 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 a spread of Nd–O bond distances ranging from 2.40–2.75 Å. 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, a cornercorner with one NdO7 pentagonal bipyramid, edges with two equivalent TaO6 octahedra, and edges with three equivalent NdO7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 45–46°. There are a spread of Nd–O bond distances ranging from 2.31–2.62 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 36°. There are four shorter (2.00 Å) and two longer (2.03 Å) Ta–O bond lengths. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent Nd3+ and two equivalent Ta5+ atoms. In the second O2- site, O2- is bonded to four Nd3+ atoms to form a mixture of corner and edge-sharing ONd4 tetrahedra. 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 4-coordinate geometry to three Nd3+ and one Ta5+ atom. In the fifth O2- site, O2- is bonded in a 4-coordinate geometry to three Nd3+ and one Ta5+ atom.