Nd3Ni8Al crystallizes in the hexagonal P6_3/mmc space group. There are two inequivalent Nd sites. In the first Nd site, Nd(1) is bonded in a 12-coordinate geometry to nine equivalent Ni(1) and three equivalent Al(1) atoms. In the second Nd site, Nd(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 Nd(2), three equivalent Nd(1), one Ni(2), one Ni(3), four equivalent Ni(1), and one Al(1) atom to form distorted NiNd5AlNi6 cuboctahedra that share corners with two equivalent Al(1)Nd6Ni6 cuboctahedra, corners with fifteen equivalent Ni(1)Nd5AlNi6 cuboctahedra, edges with eight equivalent Ni(1)Nd5AlNi6 cuboctahedra, faces with three equivalent Al(1)Nd6Ni6 cuboctahedra, and faces with eleven equivalent Ni(1)Nd5AlNi6 cuboctahedra. In the second Ni site, Ni(2) is bonded in a 9-coordinate geometry to three equivalent Nd(2) and six equivalent Ni(1) atoms. In the third Ni site, Ni(3) is bonded in a 9-coordinate geometry to three equivalent Nd(2) and six equivalent Ni(1) atoms. Al(1) is bonded to six equivalent Nd(1) and six equivalent Ni(1) atoms to form AlNd6Ni6 cuboctahedra that share corners with twelve equivalent Ni(1)Nd5AlNi6 cuboctahedra, edges with six equivalent Al(1)Nd6Ni6 cuboctahedra, and faces with eighteen equivalent Ni(1)Nd5AlNi6 cuboctahedra.
Nd3Ni8Al crystallizes in the hexagonal P6_3/mmc space group. There are two inequivalent Nd sites. In the first Nd site, Nd(1) is bonded in a 12-coordinate geometry to nine equivalent Ni(1) and three equivalent Al(1) atoms. There are six shorter (2.89 Å) and three longer (3.19 Å) Nd(1)-Ni(1) bond lengths. All Nd(1)-Al(1) bond lengths are 3.07 Å. In the second Nd site, Nd(2) is bonded in a 6-coordinate geometry to three equivalent Ni(2), three equivalent Ni(3), and twelve equivalent Ni(1) atoms. All Nd(2)-Ni(2) bond lengths are 2.97 Å. All Nd(2)-Ni(3) bond lengths are 2.97 Å. All Nd(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 Nd(2), three equivalent Nd(1), one Ni(2), one Ni(3), four equivalent Ni(1), and one Al(1) atom to form distorted NiNd5AlNi6 cuboctahedra that share corners with two equivalent Al(1)Nd6Ni6 cuboctahedra, corners with fifteen equivalent Ni(1)Nd5AlNi6 cuboctahedra, edges with eight equivalent Ni(1)Nd5AlNi6 cuboctahedra, faces with three equivalent Al(1)Nd6Ni6 cuboctahedra, and faces with eleven equivalent Ni(1)Nd5AlNi6 cuboctahedra. The Ni(1)-Ni(2) bond length is 2.48 Å. The Ni(1)-Ni(3) bond length is 2.50 Å. There are two shorter (2.55 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 Nd(2) and six equivalent Ni(1) atoms. In the third Ni site, Ni(3) is bonded in a 9-coordinate geometry to three equivalent Nd(2) and six equivalent Ni(1) atoms. Al(1) is bonded to six equivalent Nd(1) and six equivalent Ni(1) atoms to form AlNd6Ni6 cuboctahedra that share corners with twelve equivalent Ni(1)Nd5AlNi6 cuboctahedra, edges with six equivalent Al(1)Nd6Ni6 cuboctahedra, and faces with eighteen equivalent Ni(1)Nd5AlNi6 cuboctahedra.