Materials Data on GdAl4Ge2Au by Materials Project

Abstract

GdAuAl4Ge2 crystallizes in the trigonal R-3m space group. The structure is three-dimensional. Gd is bonded to six equivalent Ge atoms to form GdGe6 octahedra that share corners with twelve AlGeAu3 tetrahedra, edges with six equivalent GdGe6 octahedra, and edges with six equivalent AlGe3Au tetrahedra. All Gd–Ge bond lengths are 3.23 Å. Au is bonded in a body-centered cubic geometry to eight Al atoms. There are six shorter (2.75 Å) and two longer (2.81 Å) Au–Al bond lengths. There are two inequivalent Al sites. In the first Al site, Al is bonded to three equivalent Au and one Ge atom to form AlGeAu3 tetrahedra that share corners with three equivalent GdGe6 octahedra, corners with twelve AlGeAu3 tetrahedra, and edges with six AlGeAu3 tetrahedra. The corner-sharing octahedral tilt angles are 54°. The Al–Ge bond length is 2.82 Å. In the second Al site, Al is bonded to one Au and three equivalent Ge atoms to form AlGe3Au tetrahedra that share corners with three equivalent GdGe6 octahedra, corners with ten AlGeAu3 tetrahedra, edges with three equivalent GdGe6 octahedra, and edges with three equivalent AlGeAu3 tetrahedra. The corner-sharing octahedral tilt angles are 17°. All Al–Ge bond lengths are 2.76 Å. Ge is bonded to three equivalent Gd and four Al atoms to form a mixture of distorted corner and edge-sharing GeGd3Al4 pentagonal bipyramids.