Yb4(Pt3Al8)3 crystallizes in the triclinic P-1 space group. There are two inequivalent Yb sites. In the first Yb site, Yb(1) is bonded in a 17-coordinate geometry to one Pt(1), one Pt(3), one Pt(4), one Pt(5), two equivalent Pt(2), one Al(10), one Al(11), one Al(12), one Al(3), one Al(4), one Al(5), one Al(6), one Al(7), one Al(8), and two equivalent Al(1) atoms. In the second Yb site, Yb(2) is bonded in a 17-coordinate geometry to one Pt(1), one Pt(3), one Pt(4), one Pt(5), two equivalent Pt(2), one Al(1), one Al(10), one Al(11), one Al(12), one Al(4), one Al(5), one Al(6), one Al(8), one Al(9), and two equivalent Al(7) atoms. There are five inequivalent Pt sites. In the first Pt site, Pt(1) is bonded in a 8-coordinate geometry to one Yb(1), one Yb(2), one Al(11), one Al(2), one Al(3), one Al(4), one Al(5), one Al(6), and two equivalent Al(9) atoms. In the second Pt site, Pt(2) is bonded in a 8-coordinate geometry to two equivalent Yb(1), two equivalent Yb(2), one Al(10), one Al(12), two equivalent Al(1), two equivalent Al(7), and two equivalent Al(8) atoms. In the third Pt site, Pt(3) is bonded in a 8-coordinate geometry to one Yb(1), one Yb(2), one Al(10), one Al(2), one Al(4), one Al(5), one Al(6), one Al(9), and two equivalent Al(3) atoms. In the fourth Pt site, Pt(4) is bonded in a 8-coordinate geometry to one Yb(1), one Yb(2), one Al(12), one Al(3), one Al(4), one Al(5), one Al(6), one Al(9), and two equivalent Al(2) atoms. In the fifth Pt site, Pt(5) is bonded in a 8-coordinate geometry to two equivalent Yb(1), two equivalent Yb(2), two equivalent Al(1), two equivalent Al(11), two equivalent Al(7), and two equivalent Al(8) atoms. There are twelve inequivalent Al sites. In the first Al site, Al(1) is bonded in a 3-coordinate geometry to one Yb(2), two equivalent Yb(1), one Pt(5), and two equivalent Pt(2) atoms. In the second Al site, Al(2) is bonded to one Pt(1), one Pt(3), and two equivalent Pt(4) atoms to form distorted AlPt4 tetrahedra that share corners with three equivalent Al(3)YbPt4 tetrahedra, corners with three equivalent Al(9)YbPt4 tetrahedra,  an edgeedge with one Al(2)Pt4 tetrahedra,  an edgeedge with one Al(3)YbPt4 tetrahedra, and  an edgeedge with one Al(9)YbPt4 tetrahedra. In the third Al site, Al(3) is bonded to one Yb(1), one Pt(1), one Pt(4), and two equivalent Pt(3) atoms to form distorted AlYbPt4 tetrahedra that share corners with three equivalent Al(2)Pt4 tetrahedra, corners with three equivalent Al(9)YbPt4 tetrahedra,  an edgeedge with one Al(2)Pt4 tetrahedra,  an edgeedge with one Al(3)YbPt4 tetrahedra, and  an edgeedge with one Al(9)YbPt4 tetrahedra. In the fourth Al site, Al(4) is bonded in a 3-coordinate geometry to one Yb(1), one Yb(2), one Pt(1), one Pt(3), and one Pt(4) atom. In the fifth Al site, Al(5) is bonded in a 3-coordinate geometry to one Yb(1), one Yb(2), one Pt(1), one Pt(3), and one Pt(4) atom. In the sixth Al site, Al(6) is bonded in a 3-coordinate geometry to one Yb(1), one Yb(2), one Pt(1), one Pt(3), and one Pt(4) atom. In the seventh Al site, Al(7) is bonded in a 3-coordinate geometry to one Yb(1), two equivalent Yb(2), one Pt(5), and two equivalent Pt(2) atoms. In the eighth Al site, Al(8) is bonded in a 3-coordinate geometry to one Yb(1), one Yb(2), one Pt(5), and two equivalent Pt(2) atoms. In the ninth Al site, Al(9) is bonded to one Yb(2), one Pt(3), one Pt(4), and two equivalent Pt(1) atoms to form distorted AlYbPt4 tetrahedra that share corners with three equivalent Al(2)Pt4 tetrahedra, corners with three equivalent Al(3)YbPt4 tetrahedra,  an edgeedge with one Al(2)Pt4 tetrahedra,  an edgeedge with one Al(3)YbPt4 tetrahedra, and  an edgeedge with one Al(9)YbPt4 tetrahedra. In the tenth Al site, Al(10) is bonded in a 2-coordinate geometry to one Yb(1), one Yb(2), one Pt(2), and one Pt(3) atom. In the eleventh Al site, Al(11) is bonded in a 2-coordinate geometry to one Yb(1), one Yb(2), one Pt(1), and one Pt(5) atom. In the twelfth Al site, Al(12) is bonded in a 2-coordinate geometry to one Yb(1), one Yb(2), one Pt(2), and one Pt(4) atom.
Yb4(Pt3Al8)3 crystallizes in the triclinic P-1 space group. There are two inequivalent Yb sites. In the first Yb site, Yb(1) is bonded in a 17-coordinate geometry to one Pt(1), one Pt(3), one Pt(4), one Pt(5), two equivalent Pt(2), one Al(10), one Al(11), one Al(12), one Al(3), one Al(4), one Al(5), one Al(6), one Al(7), one Al(8), and two equivalent Al(1) atoms. The Yb(1)-Pt(1) bond length is 3.29 Å. The Yb(1)-Pt(3) bond length is 3.30 Å. The Yb(1)-Pt(4) bond length is 3.32 Å. The Yb(1)-Pt(5) bond length is 3.53 Å. There is one shorter (3.51 Å) and one longer (3.54 Å) Yb(1)-Pt(2) bond length. The Yb(1)-Al(10) bond length is 3.07 Å. The Yb(1)-Al(11) bond length is 3.08 Å. The Yb(1)-Al(12) bond length is 3.10 Å. The Yb(1)-Al(3) bond length is 3.22 Å. The Yb(1)-Al(4) bond length is 3.08 Å. The Yb(1)-Al(5) bond length is 3.08 Å. The Yb(1)-Al(6) bond length is 3.09 Å. The Yb(1)-Al(7) bond length is 3.09 Å. The Yb(1)-Al(8) bond length is 3.15 Å. There is one shorter (3.10 Å) and one longer (3.19 Å) Yb(1)-Al(1) bond length. In the second Yb site, Yb(2) is bonded in a 17-coordinate geometry to one Pt(1), one Pt(3), one Pt(4), one Pt(5), two equivalent Pt(2), one Al(1), one Al(10), one Al(11), one Al(12), one Al(4), one Al(5), one Al(6), one Al(8), one Al(9), and two equivalent Al(7) atoms. The Yb(2)-Pt(1) bond length is 3.29 Å. The Yb(2)-Pt(3) bond length is 3.30 Å. The Yb(2)-Pt(4) bond length is 3.31 Å. The Yb(2)-Pt(5) bond length is 3.53 Å. There is one shorter (3.50 Å) and one longer (3.55 Å) Yb(2)-Pt(2) bond length. The Yb(2)-Al(1) bond length is 3.09 Å. The Yb(2)-Al(10) bond length is 3.09 Å. The Yb(2)-Al(11) bond length is 3.08 Å. The Yb(2)-Al(12) bond length is 3.08 Å. The Yb(2)-Al(4) bond length is 3.08 Å. The Yb(2)-Al(5) bond length is 3.08 Å. The Yb(2)-Al(6) bond length is 3.09 Å. The Yb(2)-Al(8) bond length is 3.15 Å. The Yb(2)-Al(9) bond length is 3.22 Å. There is one shorter (3.10 Å) and one longer (3.20 Å) Yb(2)-Al(7) bond length. There are five inequivalent Pt sites. In the first Pt site, Pt(1) is bonded in a 8-coordinate geometry to one Yb(1), one Yb(2), one Al(11), one Al(2), one Al(3), one Al(4), one Al(5), one Al(6), and two equivalent Al(9) atoms. The Pt(1)-Al(11) bond length is 2.53 Å. The Pt(1)-Al(2) bond length is 2.74 Å. The Pt(1)-Al(3) bond length is 2.66 Å. The Pt(1)-Al(4) bond length is 2.54 Å. The Pt(1)-Al(5) bond length is 2.53 Å. The Pt(1)-Al(6) bond length is 2.52 Å. There is one shorter (2.55 Å) and one longer (2.66 Å) Pt(1)-Al(9) bond length. In the second Pt site, Pt(2) is bonded in a 8-coordinate geometry to two equivalent Yb(1), two equivalent Yb(2), one Al(10), one Al(12), two equivalent Al(1), two equivalent Al(7), and two equivalent Al(8) atoms. The Pt(2)-Al(10) bond length is 2.58 Å. The Pt(2)-Al(12) bond length is 2.59 Å. There is one shorter (2.54 Å) and one longer (2.58 Å) Pt(2)-Al(1) bond length. There is one shorter (2.53 Å) and one longer (2.58 Å) Pt(2)-Al(7) bond length. Both Pt(2)-Al(8) bond lengths are 2.61 Å. In the third Pt site, Pt(3) is bonded in a 8-coordinate geometry to one Yb(1), one Yb(2), one Al(10), one Al(2), one Al(4), one Al(5), one Al(6), one Al(9), and two equivalent Al(3) atoms. The Pt(3)-Al(10) bond length is 2.54 Å. The Pt(3)-Al(2) bond length is 2.74 Å. The Pt(3)-Al(4) bond length is 2.53 Å. The Pt(3)-Al(5) bond length is 2.53 Å. The Pt(3)-Al(6) bond length is 2.53 Å. The Pt(3)-Al(9) bond length is 2.66 Å. There is one shorter (2.55 Å) and one longer (2.67 Å) Pt(3)-Al(3) bond length. In the fourth Pt site, Pt(4) is bonded in a 8-coordinate geometry to one Yb(1), one Yb(2), one Al(12), one Al(3), one Al(4), one Al(5), one Al(6), one Al(9), and two equivalent Al(2) atoms. The Pt(4)-Al(12) bond length is 2.54 Å. The Pt(4)-Al(3) bond length is 2.67 Å. The Pt(4)-Al(4) bond length is 2.53 Å. The Pt(4)-Al(5) bond length is 2.52 Å. The Pt(4)-Al(6) bond length is 2.52 Å. The Pt(4)-Al(9) bond length is 2.67 Å. There is one shorter (2.55 Å) and one longer (2.75 Å) Pt(4)-Al(2) bond length. In the fifth Pt site, Pt(5) is bonded in a 8-coordinate geometry to two equivalent Yb(1), two equivalent Yb(2), two equivalent Al(1), two equivalent Al(11), two equivalent Al(7), and two equivalent Al(8) atoms. Both Pt(5)-Al(1) bond lengths are 2.58 Å. Both Pt(5)-Al(11) bond lengths are 2.59 Å. Both Pt(5)-Al(7) bond lengths are 2.58 Å. Both Pt(5)-Al(8) bond lengths are 2.56 Å. There are twelve inequivalent Al sites. In the first Al site, Al(1) is bonded in a 3-coordinate geometry to one Yb(2), two equivalent Yb(1), one Pt(5), and two equivalent Pt(2) atoms. In the second Al site, Al(2) is bonded to one Pt(1), one Pt(3), and two equivalent Pt(4) atoms to form distorted AlPt4 tetrahedra that share corners with three equivalent Al(3)YbPt4 tetrahedra, corners with three equivalent Al(9)YbPt4 tetrahedra,  an edgeedge with one Al(2)Pt4 tetrahedra,  an edgeedge with one Al(3)YbPt4 tetrahedra, and  an edgeedge with one Al(9)YbPt4 tetrahedra. In the third Al site, Al(3) is bonded to one Yb(1), one Pt(1), one Pt(4), and two equivalent Pt(3) atoms to form distorted AlYbPt4 tetrahedra that share corners with three equivalent Al(2)Pt4 tetrahedra, corners with three equivalent Al(9)YbPt4 tetrahedra,  an edgeedge with one Al(2)Pt4 tetrahedra,  an edgeedge with one Al(3)YbPt4 tetrahedra, and  an edgeedge with one Al(9)YbPt4 tetrahedra. In the fourth Al site, Al(4) is bonded in a 3-coordinate geometry to one Yb(1), one Yb(2), one Pt(1), one Pt(3), and one Pt(4) atom. In the fifth Al site, Al(5) is bonded in a 3-coordinate geometry to one Yb(1), one Yb(2), one Pt(1), one Pt(3), and one Pt(4) atom. In the sixth Al site, Al(6) is bonded in a 3-coordinate geometry to one Yb(1), one Yb(2), one Pt(1), one Pt(3), and one Pt(4) atom. In the seventh Al site, Al(7) is bonded in a 3-coordinate geometry to one Yb(1), two equivalent Yb(2), one Pt(5), and two equivalent Pt(2) atoms. In the eighth Al site, Al(8) is bonded in a 3-coordinate geometry to one Yb(1), one Yb(2), one Pt(5), and two equivalent Pt(2) atoms. In the ninth Al site, Al(9) is bonded to one Yb(2), one Pt(3), one Pt(4), and two equivalent Pt(1) atoms to form distorted AlYbPt4 tetrahedra that share corners with three equivalent Al(2)Pt4 tetrahedra, corners with three equivalent Al(3)YbPt4 tetrahedra,  an edgeedge with one Al(2)Pt4 tetrahedra,  an edgeedge with one Al(3)YbPt4 tetrahedra, and  an edgeedge with one Al(9)YbPt4 tetrahedra. In the tenth Al site, Al(10) is bonded in a 2-coordinate geometry to one Yb(1), one Yb(2), one Pt(2), and one Pt(3) atom. In the eleventh Al site, Al(11) is bonded in a 2-coordinate geometry to one Yb(1), one Yb(2), one Pt(1), and one Pt(5) atom. In the twelfth Al site, Al(12) is bonded in a 2-coordinate geometry to one Yb(1), one Yb(2), one Pt(2), and one Pt(4) atom.