Pr3Ni8Al crystallizes in the hexagonal P6_3/mmc space group. There are two inequivalent Pr sites. In the first Pr site, Pr(1) is bonded in a 12-coordinate geometry to nine equivalent Ni(1) and three equivalent Al(1) atoms. In the second Pr site, Pr(2) is bonded in a 6-coordinate geometry to three equivalent Ni(2), three equivalent Ni(3), and twelve equivalent Ni(1) atoms. There are three inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to two equivalent Pr(2), three equivalent Pr(1), one Ni(2), one Ni(3), four equivalent Ni(1), and one Al(1) atom to form distorted NiPr5AlNi6 cuboctahedra that share corners with two equivalent Al(1)Pr6Ni6 cuboctahedra, corners with fifteen equivalent Ni(1)Pr5AlNi6 cuboctahedra, edges with eight equivalent Ni(1)Pr5AlNi6 cuboctahedra, faces with three equivalent Al(1)Pr6Ni6 cuboctahedra, and faces with eleven equivalent Ni(1)Pr5AlNi6 cuboctahedra. In the second Ni site, Ni(2) is bonded in a 9-coordinate geometry to three equivalent Pr(2) and six equivalent Ni(1) atoms. In the third Ni site, Ni(3) is bonded in a 9-coordinate geometry to three equivalent Pr(2) and six equivalent Ni(1) atoms. Al(1) is bonded to six equivalent Pr(1) and six equivalent Ni(1) atoms to form AlPr6Ni6 cuboctahedra that share corners with twelve equivalent Ni(1)Pr5AlNi6 cuboctahedra, edges with six equivalent Al(1)Pr6Ni6 cuboctahedra, and faces with eighteen equivalent Ni(1)Pr5AlNi6 cuboctahedra.
Pr3Ni8Al crystallizes in the hexagonal P6_3/mmc space group. There are two inequivalent Pr sites. In the first Pr site, Pr(1) is bonded in a 12-coordinate geometry to nine equivalent Ni(1) and three equivalent Al(1) atoms. There are six shorter (2.90 Å) and three longer (3.19 Å) Pr(1)-Ni(1) bond lengths. All Pr(1)-Al(1) bond lengths are 3.07 Å. In the second Pr site, Pr(2) is bonded in a 6-coordinate geometry to three equivalent Ni(2), three equivalent Ni(3), and twelve equivalent Ni(1) atoms. All Pr(2)-Ni(2) bond lengths are 2.98 Å. All Pr(2)-Ni(3) bond lengths are 2.98 Å. All Pr(2)-Ni(1) bond lengths are 3.26 Å. There are three inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to two equivalent Pr(2), three equivalent Pr(1), one Ni(2), one Ni(3), four equivalent Ni(1), and one Al(1) atom to form distorted NiPr5AlNi6 cuboctahedra that share corners with two equivalent Al(1)Pr6Ni6 cuboctahedra, corners with fifteen equivalent Ni(1)Pr5AlNi6 cuboctahedra, edges with eight equivalent Ni(1)Pr5AlNi6 cuboctahedra, faces with three equivalent Al(1)Pr6Ni6 cuboctahedra, and faces with eleven equivalent Ni(1)Pr5AlNi6 cuboctahedra. The Ni(1)-Ni(2) bond length is 2.48 Å. The Ni(1)-Ni(3) bond length is 2.49 Å. There are two shorter (2.56 Å) and two longer (2.60 Å) Ni(1)-Ni(1) bond lengths. The Ni(1)-Al(1) bond length is 2.56 Å. In the second Ni site, Ni(2) is bonded in a 9-coordinate geometry to three equivalent Pr(2) and six equivalent Ni(1) atoms. In the third Ni site, Ni(3) is bonded in a 9-coordinate geometry to three equivalent Pr(2) and six equivalent Ni(1) atoms. Al(1) is bonded to six equivalent Pr(1) and six equivalent Ni(1) atoms to form AlPr6Ni6 cuboctahedra that share corners with twelve equivalent Ni(1)Pr5AlNi6 cuboctahedra, edges with six equivalent Al(1)Pr6Ni6 cuboctahedra, and faces with eighteen equivalent Ni(1)Pr5AlNi6 cuboctahedra.