Materials Data on GdTa3O9 by Materials Project
GdTa3O9 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. Gd3+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Gd–O bond distances ranging from 2.38–2.55 Å. There are two inequivalent Ta5+ sites. In the first Ta5+ site, Ta5+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with two equivalent TaO6 octahedra, corners with two equivalent TaO7 pentagonal bipyramids, and edges with two equivalent TaO7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 34°. There are a spread of Ta–O bond distances ranging from 1.98–2.01 Å. In the second Ta5+ site, Ta5+ is bonded to seven O2- atoms to form TaO7 pentagonal bipyramids that share a cornercorner with one TaO6 octahedra, corners with two equivalent TaO7 pentagonal bipyramids, an edgeedge with one TaO6 octahedra, and edges with two equivalent TaO7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 39°. There are a spread of Ta–O bond distances ranging from 1.92–2.22 Å. There are six inequivalent O2- sites. In the first O2- site, O2- is bonded in a 2-coordinate geometry to one Gd3+ and two equivalent Ta5+ atoms. In the second O2- site, O2- is bonded in a 3-coordinate geometry to one Gd3+ and two equivalent Ta5+ atoms. In the third O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Gd3+ and two Ta5+ atoms. In the fourth O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to one Gd3+ and two equivalent Ta5+ atoms. In the fifth O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to three Ta5+ atoms. In the sixth O2- site, O2- is bonded in a bent 150 degrees geometry to two equivalent Ta5+ atoms.