Al11Pr3 crystallizes in the orthorhombic Immm space group. There are two inequivalent Pr sites. In the first Pr site, Pr(1) is bonded to four equivalent Al(2), four equivalent Al(4), and eight equivalent Al(3) atoms to form distorted PrAl16 cuboctahedra that share corners with four equivalent Al(1)Pr4Al8 cuboctahedra, faces with two equivalent Pr(1)Al16 cuboctahedra, faces with two equivalent Al(1)Pr4Al8 cuboctahedra, and faces with four equivalent Al(2)Pr4Al8 cuboctahedra. In the second Pr site, Pr(2) is bonded in a 12-coordinate geometry to two equivalent Al(1), two equivalent Al(2), four equivalent Al(3), and six equivalent Al(4) atoms. There are four inequivalent Al sites. In the first Al site, Al(1) is bonded to four equivalent Pr(2), four equivalent Al(2), and four equivalent Al(4) atoms to form distorted AlPr4Al8 cuboctahedra that share corners with four equivalent Pr(1)Al16 cuboctahedra, faces with two equivalent Pr(1)Al16 cuboctahedra, faces with two equivalent Al(1)Pr4Al8 cuboctahedra, and faces with four equivalent Al(2)Pr4Al8 cuboctahedra. In the second Al site, Al(2) is bonded to two equivalent Pr(1), two equivalent Pr(2), two equivalent Al(1), two equivalent Al(3), and four equivalent Al(4) atoms to form distorted AlPr4Al8 cuboctahedra that share corners with four equivalent Al(2)Pr4Al8 cuboctahedra,  an edgeedge with one Al(2)Pr4Al8 cuboctahedra, faces with two equivalent Pr(1)Al16 cuboctahedra, faces with two equivalent Al(1)Pr4Al8 cuboctahedra, and faces with three equivalent Al(2)Pr4Al8 cuboctahedra. In the third Al site, Al(3) is bonded in a 9-coordinate geometry to two equivalent Pr(1), two equivalent Pr(2), one Al(2), one Al(3), and three equivalent Al(4) atoms. In the fourth Al site, Al(4) is bonded in a 10-coordinate geometry to one Pr(1), three equivalent Pr(2), one Al(1), two equivalent Al(2), and three equivalent Al(3) atoms.
Al11Pr3 crystallizes in the orthorhombic Immm space group. There are two inequivalent Pr sites. In the first Pr site, Pr(1) is bonded to four equivalent Al(2), four equivalent Al(4), and eight equivalent Al(3) atoms to form distorted PrAl16 cuboctahedra that share corners with four equivalent Al(1)Pr4Al8 cuboctahedra, faces with two equivalent Pr(1)Al16 cuboctahedra, faces with two equivalent Al(1)Pr4Al8 cuboctahedra, and faces with four equivalent Al(2)Pr4Al8 cuboctahedra. All Pr(1)-Al(2) bond lengths are 3.59 Å. All Pr(1)-Al(4) bond lengths are 3.27 Å. All Pr(1)-Al(3) bond lengths are 3.35 Å. In the second Pr site, Pr(2) is bonded in a 12-coordinate geometry to two equivalent Al(1), two equivalent Al(2), four equivalent Al(3), and six equivalent Al(4) atoms. Both Pr(2)-Al(1) bond lengths are 3.23 Å. Both Pr(2)-Al(2) bond lengths are 3.22 Å. All Pr(2)-Al(3) bond lengths are 3.23 Å. There are four shorter (3.21 Å) and two longer (3.62 Å) Pr(2)-Al(4) bond lengths. There are four inequivalent Al sites. In the first Al site, Al(1) is bonded to four equivalent Pr(2), four equivalent Al(2), and four equivalent Al(4) atoms to form distorted AlPr4Al8 cuboctahedra that share corners with four equivalent Pr(1)Al16 cuboctahedra, faces with two equivalent Pr(1)Al16 cuboctahedra, faces with two equivalent Al(1)Pr4Al8 cuboctahedra, and faces with four equivalent Al(2)Pr4Al8 cuboctahedra. All Al(1)-Al(2) bond lengths are 3.08 Å. All Al(1)-Al(4) bond lengths are 2.87 Å. In the second Al site, Al(2) is bonded to two equivalent Pr(1), two equivalent Pr(2), two equivalent Al(1), two equivalent Al(3), and four equivalent Al(4) atoms to form distorted AlPr4Al8 cuboctahedra that share corners with four equivalent Al(2)Pr4Al8 cuboctahedra,  an edgeedge with one Al(2)Pr4Al8 cuboctahedra, faces with two equivalent Pr(1)Al16 cuboctahedra, faces with two equivalent Al(1)Pr4Al8 cuboctahedra, and faces with three equivalent Al(2)Pr4Al8 cuboctahedra. Both Al(2)-Al(3) bond lengths are 2.64 Å. All Al(2)-Al(4) bond lengths are 2.82 Å. In the third Al site, Al(3) is bonded in a 9-coordinate geometry to two equivalent Pr(1), two equivalent Pr(2), one Al(2), one Al(3), and three equivalent Al(4) atoms. The Al(3)-Al(3) bond length is 2.65 Å. There are two shorter (2.64 Å) and one longer (2.74 Å) Al(3)-Al(4) bond length. In the fourth Al site, Al(4) is bonded in a 10-coordinate geometry to one Pr(1), three equivalent Pr(2), one Al(1), two equivalent Al(2), and three equivalent Al(3) atoms.