Yb7Al5Ge8 crystallizes in the monoclinic C2/m space group. There are four inequivalent Yb sites. In the first Yb site, Yb(1) is bonded in a 5-coordinate geometry to two equivalent Al(3), two equivalent Ge(4), and three equivalent Ge(2) atoms. In the second Yb site, Yb(2) is bonded in a 5-coordinate geometry to two equivalent Ge(3), two equivalent Ge(4), and three equivalent Ge(1) atoms. In the third Yb site, Yb(3) is bonded in a 11-coordinate geometry to one Al(1), two equivalent Al(2), two equivalent Al(3), two equivalent Ge(2), two equivalent Ge(3), and two equivalent Ge(4) atoms. In the fourth Yb site, Yb(4) is bonded to two equivalent Ge(1) and four equivalent Ge(3) atoms to form YbGe6 octahedra that share corners with two equivalent Al(1)YbGe4 tetrahedra and edges with two equivalent Yb(4)Ge6 octahedra. There are three inequivalent Al sites. In the first Al site, Al(1) is bonded to one Yb(3), one Ge(1), one Ge(4), and two equivalent Ge(2) atoms to form distorted AlYbGe4 tetrahedra that share  a cornercorner with one Al(3)Yb8Ge4 cuboctahedra,  a cornercorner with one Yb(4)Ge6 octahedra, corners with two equivalent Al(1)YbGe4 tetrahedra, and edges with two equivalent Al(3)Yb8Ge4 cuboctahedra. The corner-sharing octahedral tilt angles are 51°. In the second Al site, Al(2) is bonded in a 4-coordinate geometry to two equivalent Yb(3), one Ge(2), one Ge(3), and two equivalent Ge(1) atoms. In the third Al site, Al(3) is bonded to four equivalent Yb(1), four equivalent Yb(3), two equivalent Ge(2), and two equivalent Ge(4) atoms to form AlYb8Ge4 cuboctahedra that share corners with two equivalent Al(1)YbGe4 tetrahedra, edges with four equivalent Al(1)YbGe4 tetrahedra, and faces with two equivalent Al(3)Yb8Ge4 cuboctahedra. There are four inequivalent Ge sites. In the first Ge site, Ge(1) is bonded in a 7-coordinate geometry to one Yb(4), three equivalent Yb(2), one Al(1), and two equivalent Al(2) atoms. In the second Ge site, Ge(2) is bonded in a 9-coordinate geometry to two equivalent Yb(3), three equivalent Yb(1), one Al(2), one Al(3), and two equivalent Al(1) atoms. In the third Ge site, Ge(3) is bonded in a 8-coordinate geometry to two equivalent Yb(2), two equivalent Yb(3), two equivalent Yb(4), one Al(2), and one Ge(4) atom. In the fourth Ge site, Ge(4) is bonded in a 9-coordinate geometry to two equivalent Yb(1), two equivalent Yb(2), two equivalent Yb(3), one Al(1), one Al(3), and one Ge(3) atom.
Yb7Al5Ge8 crystallizes in the monoclinic C2/m space group. There are four inequivalent Yb sites. In the first Yb site, Yb(1) is bonded in a 5-coordinate geometry to two equivalent Al(3), two equivalent Ge(4), and three equivalent Ge(2) atoms. Both Yb(1)-Al(3) bond lengths are 3.31 Å. Both Yb(1)-Ge(4) bond lengths are 2.92 Å. There are two shorter (2.94 Å) and one longer (3.05 Å) Yb(1)-Ge(2) bond length. In the second Yb site, Yb(2) is bonded in a 5-coordinate geometry to two equivalent Ge(3), two equivalent Ge(4), and three equivalent Ge(1) atoms. Both Yb(2)-Ge(3) bond lengths are 3.01 Å. Both Yb(2)-Ge(4) bond lengths are 3.31 Å. There are two shorter (3.02 Å) and one longer (3.05 Å) Yb(2)-Ge(1) bond length. In the third Yb site, Yb(3) is bonded in a 11-coordinate geometry to one Al(1), two equivalent Al(2), two equivalent Al(3), two equivalent Ge(2), two equivalent Ge(3), and two equivalent Ge(4) atoms. The Yb(3)-Al(1) bond length is 3.28 Å. Both Yb(3)-Al(2) bond lengths are 3.12 Å. Both Yb(3)-Al(3) bond lengths are 3.34 Å. Both Yb(3)-Ge(2) bond lengths are 3.12 Å. Both Yb(3)-Ge(3) bond lengths are 3.02 Å. Both Yb(3)-Ge(4) bond lengths are 2.98 Å. In the fourth Yb site, Yb(4) is bonded to two equivalent Ge(1) and four equivalent Ge(3) atoms to form YbGe6 octahedra that share corners with two equivalent Al(1)YbGe4 tetrahedra and edges with two equivalent Yb(4)Ge6 octahedra. Both Yb(4)-Ge(1) bond lengths are 2.99 Å. All Yb(4)-Ge(3) bond lengths are 2.98 Å. There are three inequivalent Al sites. In the first Al site, Al(1) is bonded to one Yb(3), one Ge(1), one Ge(4), and two equivalent Ge(2) atoms to form distorted AlYbGe4 tetrahedra that share  a cornercorner with one Al(3)Yb8Ge4 cuboctahedra,  a cornercorner with one Yb(4)Ge6 octahedra, corners with two equivalent Al(1)YbGe4 tetrahedra, and edges with two equivalent Al(3)Yb8Ge4 cuboctahedra. The corner-sharing octahedral tilt angles are 51°. The Al(1)-Ge(1) bond length is 2.53 Å. The Al(1)-Ge(4) bond length is 2.58 Å. Both Al(1)-Ge(2) bond lengths are 2.64 Å. In the second Al site, Al(2) is bonded in a 4-coordinate geometry to two equivalent Yb(3), one Ge(2), one Ge(3), and two equivalent Ge(1) atoms. The Al(2)-Ge(2) bond length is 2.66 Å. The Al(2)-Ge(3) bond length is 2.57 Å. Both Al(2)-Ge(1) bond lengths are 2.54 Å. In the third Al site, Al(3) is bonded to four equivalent Yb(1), four equivalent Yb(3), two equivalent Ge(2), and two equivalent Ge(4) atoms to form AlYb8Ge4 cuboctahedra that share corners with two equivalent Al(1)YbGe4 tetrahedra, edges with four equivalent Al(1)YbGe4 tetrahedra, and faces with two equivalent Al(3)Yb8Ge4 cuboctahedra. Both Al(3)-Ge(2) bond lengths are 2.99 Å. Both Al(3)-Ge(4) bond lengths are 2.83 Å. There are four inequivalent Ge sites. In the first Ge site, Ge(1) is bonded in a 7-coordinate geometry to one Yb(4), three equivalent Yb(2), one Al(1), and two equivalent Al(2) atoms. In the second Ge site, Ge(2) is bonded in a 9-coordinate geometry to two equivalent Yb(3), three equivalent Yb(1), one Al(2), one Al(3), and two equivalent Al(1) atoms. In the third Ge site, Ge(3) is bonded in a 8-coordinate geometry to two equivalent Yb(2), two equivalent Yb(3), two equivalent Yb(4), one Al(2), and one Ge(4) atom. The Ge(3)-Ge(4) bond length is 2.49 Å. In the fourth Ge site, Ge(4) is bonded in a 9-coordinate geometry to two equivalent Yb(1), two equivalent Yb(2), two equivalent Yb(3), one Al(1), one Al(3), and one Ge(3) atom.