Materials Data on Yb7Al5Ge8 by Materials Project

Abstract

Yb7Al5Ge8 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. there are four inequivalent Yb sites. In the first Yb site, Yb is bonded in a 5-coordinate geometry to two equivalent Al and five Ge atoms. Both Yb–Al bond lengths are 3.34 Å. There are a spread of Yb–Ge bond distances ranging from 2.95–3.09 Å. In the second Yb site, Yb is bonded in a 5-coordinate geometry to three Al and seven Ge atoms. There are one shorter (3.33 Å) and two longer (3.43 Å) Yb–Al bond lengths. There are a spread of Yb–Ge bond distances ranging from 3.04–3.31 Å. In the third Yb site, Yb is bonded in a 11-coordinate geometry to five Al and six Ge atoms. There are a spread of Yb–Al bond distances ranging from 3.14–3.39 Å. There are a spread of Yb–Ge bond distances ranging from 3.01–3.14 Å. In the fourth Yb site, Yb is bonded to six Ge atoms to form distorted YbGe6 octahedra that share corners with two equivalent AlYb3Ge4 tetrahedra and edges with two equivalent YbGe6 octahedra. There are four shorter (2.98 Å) and two longer (3.01 Å) Yb–Ge bond lengths. There are three inequivalent Al sites. In the first Al site, Al is bonded to three Yb and four Ge atoms to form distorted AlYb3Ge4 tetrahedra that share a cornercorner with one AlYb8Ge4 cuboctahedra, a cornercorner with one YbGe6 octahedra, edges with two equivalent AlYb8Ge4 cuboctahedra, and edges with two equivalent AlYb3Ge4 tetrahedra. The corner-sharing octahedral tilt angles are 52°. There are a spread of Al–Ge bond distances ranging from 2.56–2.67 Å. In the second Al site, Al is bonded in a 4-coordinate geometry to three Yb and four Ge atoms. There are a spread of Al–Ge bond distances ranging from 2.57–2.71 Å. In the third Al site, Al is bonded to eight Yb and four Ge atoms to form distorted AlYb8Ge4 cuboctahedra that share corners with two equivalent AlYb3Ge4 tetrahedra, edges with four equivalent AlYb3Ge4 tetrahedra, and faces with two equivalent AlYb8Ge4 cuboctahedra. There are two shorter (2.84 Å) and two longer (3.01 Å) Al–Ge bond lengths. There are four inequivalent Ge sites. In the first Ge site, Ge is bonded in a 7-coordinate geometry to four Yb and three Al atoms. In the second Ge site, Ge is bonded in a 9-coordinate geometry to five Yb and four Al atoms. In the third Ge site, Ge is bonded in a 8-coordinate geometry to six Yb, one Al, and one Ge atom. The Ge–Ge bond length is 2.53 Å. In the fourth Ge site, Ge is bonded in a 9-coordinate geometry to six Yb, two Al, and one Ge atom.