Materials Data on Dy2Al6Si4Au by Materials Project

Dy2AuAl6Si4 crystallizes in the trigonal R-3m space group. The structure is three-dimensional. Dy is bonded to six Si atoms to form distorted DySi6 octahedra that share corners with twelve AlSi3Au tetrahedra, edges with six equivalent DySi6 octahedra, and edges with six AlSi3Au tetrahedra. There are three shorter (2.96 Å) and three longer (2.97 Å) Dy–Si bond lengths. Au is bonded in a body-centered cubic geometry to eight Al atoms. There are six shorter (2.57 Å) and two longer (2.63 Å) Au–Al bond lengths. There are three inequivalent Al sites. In the first Al site, Al is bonded to four equivalent Si atoms to form distorted AlSi4 tetrahedra that share corners with six equivalent DySi6 octahedra, corners with six equivalent AlSi4 tetrahedra, edges with three equivalent DySi6 octahedra, and edges with three equivalent AlSi4 tetrahedra. The corner-sharing octahedra tilt angles range from 20–55°. There are three shorter (2.51 Å) and one longer (2.54 Å) Al–Si bond lengths. In the second Al site, Al is bonded to one Au and three equivalent Si atoms to form AlSi3Au tetrahedra that share corners with three equivalent DySi6 octahedra, corners with ten AlSi3Au tetrahedra, edges with three equivalent DySi6 octahedra, and edges with three equivalent AlSiAu3 tetrahedra. The corner-sharing octahedral tilt angles are 17°. All Al–Si bond lengths are 2.55 Å. In the third Al site, Al is bonded to three equivalent Au and one Si atom to form distorted AlSiAu3 tetrahedra that share corners with three equivalent DySi6 octahedra, corners with twelve AlSi3Au tetrahedra, and edges with six AlSi3Au tetrahedra. The corner-sharing octahedral tilt angles are 55°. The Al–Si bond length is 2.58 Å. There are two inequivalent Si sites. In the first Si site, Si is bonded to three equivalent Dy and four Al atoms to form a mixture of distorted corner and edge-sharing SiDy3Al4 pentagonal bipyramids. In the second Si site, Si is bonded to three equivalent Dy and four equivalent Al atoms to form a mixture of distorted corner and edge-sharing SiDy3Al4 pentagonal bipyramids.