Pr6Fe11Al3 crystallizes in the tetragonal I4cm space group. There are four inequivalent Pr sites. In the first Pr site, Pr(1) is bonded in a 6-coordinate geometry to one Fe(1), three equivalent Fe(5), and two equivalent Al(1) atoms. In the second Pr site, Pr(2) is bonded in a 6-coordinate geometry to one Fe(2), two equivalent Al(1), and three equivalent Al(2) atoms. In the third Pr site, Pr(3) is bonded in a 13-coordinate geometry to four equivalent Fe(2), four equivalent Fe(3), one Al(1), and four equivalent Al(2) atoms. In the fourth Pr site, Pr(4) is bonded in a 13-coordinate geometry to four equivalent Fe(1), four equivalent Fe(3), four equivalent Fe(5), and one Al(1) atom. There are five inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a 12-coordinate geometry to one Pr(1), two equivalent Pr(4), one Fe(2), one Fe(4), three equivalent Fe(5), and four equivalent Fe(3) atoms. In the second Fe site, Fe(2) is bonded in a 12-coordinate geometry to one Pr(2), two equivalent Pr(3), one Fe(1), one Fe(4), four equivalent Fe(3), and three equivalent Al(2) atoms. In the third Fe site, Fe(3) is bonded to one Pr(3), one Pr(4), one Fe(4), one Fe(5), two equivalent Fe(1), two equivalent Fe(2), three equivalent Fe(3), and one Al(2) atom to form FePr2AlFe9 cuboctahedra that share  a cornercorner with one Fe(4)Al2Fe10 cuboctahedra, corners with two equivalent Fe(5)Pr5Fe7 cuboctahedra, corners with three equivalent Fe(3)Pr2AlFe9 cuboctahedra, faces with two equivalent Fe(4)Al2Fe10 cuboctahedra, faces with four equivalent Fe(5)Pr5Fe7 cuboctahedra, and faces with seven equivalent Fe(3)Pr2AlFe9 cuboctahedra. In the fourth Fe site, Fe(4) is bonded to two equivalent Fe(1), two equivalent Fe(2), two equivalent Fe(5), four equivalent Fe(3), and two equivalent Al(2) atoms to form FeAl2Fe10 cuboctahedra that share corners with two equivalent Fe(5)Pr5Fe7 cuboctahedra, corners with four equivalent Fe(3)Pr2AlFe9 cuboctahedra, faces with two equivalent Fe(5)Pr5Fe7 cuboctahedra, and faces with eight equivalent Fe(3)Pr2AlFe9 cuboctahedra. In the fifth Fe site, Fe(5) is bonded to two equivalent Pr(4), three equivalent Pr(1), one Fe(4), one Fe(5), two equivalent Fe(3), and three equivalent Fe(1) atoms to form distorted FePr5Fe7 cuboctahedra that share  a cornercorner with one Fe(4)Al2Fe10 cuboctahedra, corners with two equivalent Fe(5)Pr5Fe7 cuboctahedra, corners with four equivalent Fe(3)Pr2AlFe9 cuboctahedra,  a faceface with one Fe(4)Al2Fe10 cuboctahedra, faces with five equivalent Fe(5)Pr5Fe7 cuboctahedra, and faces with eight equivalent Fe(3)Pr2AlFe9 cuboctahedra. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded in a distorted q6 geometry to one Pr(3), one Pr(4), four equivalent Pr(1), and four equivalent Pr(2) atoms. In the second Al site, Al(2) is bonded in a 12-coordinate geometry to two equivalent Pr(3), three equivalent Pr(2), one Fe(4), two equivalent Fe(3), three equivalent Fe(2), and one Al(2) atom.
Pr6Fe11Al3 crystallizes in the tetragonal I4cm space group. There are four inequivalent Pr sites. In the first Pr site, Pr(1) is bonded in a 6-coordinate geometry to one Fe(1), three equivalent Fe(5), and two equivalent Al(1) atoms. The Pr(1)-Fe(1) bond length is 2.98 Å. There are two shorter (3.15 Å) and one longer (3.33 Å) Pr(1)-Fe(5) bond length. Both Pr(1)-Al(1) bond lengths are 3.38 Å. In the second Pr site, Pr(2) is bonded in a 6-coordinate geometry to one Fe(2), two equivalent Al(1), and three equivalent Al(2) atoms. The Pr(2)-Fe(2) bond length is 3.18 Å. Both Pr(2)-Al(1) bond lengths are 3.32 Å. There are two shorter (3.30 Å) and one longer (3.36 Å) Pr(2)-Al(2) bond length. In the third Pr site, Pr(3) is bonded in a 13-coordinate geometry to four equivalent Fe(2), four equivalent Fe(3), one Al(1), and four equivalent Al(2) atoms. All Pr(3)-Fe(2) bond lengths are 3.21 Å. All Pr(3)-Fe(3) bond lengths are 3.08 Å. The Pr(3)-Al(1) bond length is 3.39 Å. All Pr(3)-Al(2) bond lengths are 3.25 Å. In the fourth Pr site, Pr(4) is bonded in a 13-coordinate geometry to four equivalent Fe(1), four equivalent Fe(3), four equivalent Fe(5), and one Al(1) atom. All Pr(4)-Fe(1) bond lengths are 3.17 Å. All Pr(4)-Fe(3) bond lengths are 3.04 Å. All Pr(4)-Fe(5) bond lengths are 3.28 Å. The Pr(4)-Al(1) bond length is 3.38 Å. There are five inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a 12-coordinate geometry to one Pr(1), two equivalent Pr(4), one Fe(2), one Fe(4), three equivalent Fe(5), and four equivalent Fe(3) atoms. The Fe(1)-Fe(2) bond length is 2.68 Å. The Fe(1)-Fe(4) bond length is 2.45 Å. There is one shorter (2.52 Å) and two longer (2.56 Å) Fe(1)-Fe(5) bond lengths. There are two shorter (2.46 Å) and two longer (2.58 Å) Fe(1)-Fe(3) bond lengths. In the second Fe site, Fe(2) is bonded in a 12-coordinate geometry to one Pr(2), two equivalent Pr(3), one Fe(1), one Fe(4), four equivalent Fe(3), and three equivalent Al(2) atoms. The Fe(2)-Fe(4) bond length is 2.41 Å. There are two shorter (2.48 Å) and two longer (2.55 Å) Fe(2)-Fe(3) bond lengths. There is one shorter (2.51 Å) and two longer (2.58 Å) Fe(2)-Al(2) bond lengths. In the third Fe site, Fe(3) is bonded to one Pr(3), one Pr(4), one Fe(4), one Fe(5), two equivalent Fe(1), two equivalent Fe(2), three equivalent Fe(3), and one Al(2) atom to form FePr2AlFe9 cuboctahedra that share  a cornercorner with one Fe(4)Al2Fe10 cuboctahedra, corners with two equivalent Fe(5)Pr5Fe7 cuboctahedra, corners with three equivalent Fe(3)Pr2AlFe9 cuboctahedra, faces with two equivalent Fe(4)Al2Fe10 cuboctahedra, faces with four equivalent Fe(5)Pr5Fe7 cuboctahedra, and faces with seven equivalent Fe(3)Pr2AlFe9 cuboctahedra. The Fe(3)-Fe(4) bond length is 2.41 Å. The Fe(3)-Fe(5) bond length is 2.62 Å. There is one shorter (2.53 Å) and two longer (2.54 Å) Fe(3)-Fe(3) bond lengths. The Fe(3)-Al(2) bond length is 2.63 Å. In the fourth Fe site, Fe(4) is bonded to two equivalent Fe(1), two equivalent Fe(2), two equivalent Fe(5), four equivalent Fe(3), and two equivalent Al(2) atoms to form FeAl2Fe10 cuboctahedra that share corners with two equivalent Fe(5)Pr5Fe7 cuboctahedra, corners with four equivalent Fe(3)Pr2AlFe9 cuboctahedra, faces with two equivalent Fe(5)Pr5Fe7 cuboctahedra, and faces with eight equivalent Fe(3)Pr2AlFe9 cuboctahedra. Both Fe(4)-Fe(5) bond lengths are 2.52 Å. Both Fe(4)-Al(2) bond lengths are 2.59 Å. In the fifth Fe site, Fe(5) is bonded to two equivalent Pr(4), three equivalent Pr(1), one Fe(4), one Fe(5), two equivalent Fe(3), and three equivalent Fe(1) atoms to form distorted FePr5Fe7 cuboctahedra that share  a cornercorner with one Fe(4)Al2Fe10 cuboctahedra, corners with two equivalent Fe(5)Pr5Fe7 cuboctahedra, corners with four equivalent Fe(3)Pr2AlFe9 cuboctahedra,  a faceface with one Fe(4)Al2Fe10 cuboctahedra, faces with five equivalent Fe(5)Pr5Fe7 cuboctahedra, and faces with eight equivalent Fe(3)Pr2AlFe9 cuboctahedra. The Fe(5)-Fe(5) bond length is 2.58 Å. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded in a distorted q6 geometry to one Pr(3), one Pr(4), four equivalent Pr(1), and four equivalent Pr(2) atoms. In the second Al site, Al(2) is bonded in a 12-coordinate geometry to two equivalent Pr(3), three equivalent Pr(2), one Fe(4), two equivalent Fe(3), three equivalent Fe(2), and one Al(2) atom. The Al(2)-Al(2) bond length is 2.71 Å.