Materials Data on Gd3AsO7 by Materials Project

Abstract

Gd3AsO7 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 AsO6 octahedra, a cornercorner with one GdO7 pentagonal bipyramid, edges with two equivalent AsO6 octahedra, and edges with three equivalent GdO7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 43–45°. There are a spread of Gd–O bond distances ranging from 2.23–2.52 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 2.31–2.80 Å. As5+ is bonded to six O2- atoms to form AsO6 octahedra that share corners with two equivalent AsO6 octahedra, corners with four equivalent GdO7 pentagonal bipyramids, and edges with four equivalent GdO7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 36°. There are a spread of As–O bond distances ranging from 1.85–1.96 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 As5+ atoms. In the second O2- site, O2- is bonded to four Gd3+ atoms to form a mixture of corner and edge-sharing OGd4 tetrahedra. In the third O2- site, O2- is bonded in a 4-coordinate geometry to three Gd3+ and one As5+ atom. In the fourth O2- site, O2- is bonded to four Gd3+ atoms to form a mixture of corner and edge-sharing OGd4 tetrahedra. In the fifth O2- site, O2- is bonded in a 4-coordinate geometry to three Gd3+ and one As5+ atom.