Pu2Ni17 crystallizes in the hexagonal P6_3/mmc space group. There are two inequivalent Pu sites. In the first Pu site, Pu(1) is bonded in a 18-coordinate geometry to six equivalent Ni(1) and twelve equivalent Ni(4) atoms. In the second Pu site, Pu(2) is bonded in a 20-coordinate geometry to two equivalent Ni(2), six equivalent Ni(1), six equivalent Ni(3), and six equivalent Ni(4) atoms. There are four inequivalent Ni sites. In the first Ni site, Ni(1) is bonded in a 12-coordinate geometry to one Pu(1), one Pu(2), two equivalent Ni(1), two equivalent Ni(2), two equivalent Ni(3), and four equivalent Ni(4) atoms. In the second Ni site, Ni(2) is bonded in a 14-coordinate geometry to one Pu(2), one Ni(2), three equivalent Ni(3), three equivalent Ni(4), and six equivalent Ni(1) atoms. In the third Ni site, Ni(3) is bonded to two equivalent Pu(2), two equivalent Ni(2), four equivalent Ni(1), and four equivalent Ni(4) atoms to form NiPu2Ni10 cuboctahedra that share corners with four equivalent Ni(3)Pu2Ni10 cuboctahedra, corners with ten equivalent Ni(4)Pu3Ni9 cuboctahedra, edges with six equivalent Ni(4)Pu3Ni9 cuboctahedra, faces with four equivalent Ni(4)Pu3Ni9 cuboctahedra, and faces with six equivalent Ni(3)Pu2Ni10 cuboctahedra. In the fourth Ni site, Ni(4) is bonded to one Pu(2), two equivalent Pu(1), one Ni(2), two equivalent Ni(3), two equivalent Ni(4), and four equivalent Ni(1) atoms to form distorted NiPu3Ni9 cuboctahedra that share corners with five equivalent Ni(3)Pu2Ni10 cuboctahedra, corners with ten equivalent Ni(4)Pu3Ni9 cuboctahedra, edges with three equivalent Ni(3)Pu2Ni10 cuboctahedra, edges with five equivalent Ni(4)Pu3Ni9 cuboctahedra, faces with two equivalent Ni(3)Pu2Ni10 cuboctahedra, and faces with eight equivalent Ni(4)Pu3Ni9 cuboctahedra.
Pu2Ni17 crystallizes in the hexagonal P6_3/mmc space group. There are two inequivalent Pu sites. In the first Pu site, Pu(1) is bonded in a 18-coordinate geometry to six equivalent Ni(1) and twelve equivalent Ni(4) atoms. All Pu(1)-Ni(1) bond lengths are 2.89 Å. There are six shorter (2.98 Å) and six longer (3.21 Å) Pu(1)-Ni(4) bond lengths. In the second Pu site, Pu(2) is bonded in a 20-coordinate geometry to two equivalent Ni(2), six equivalent Ni(1), six equivalent Ni(3), and six equivalent Ni(4) atoms. Both Pu(2)-Ni(2) bond lengths are 2.79 Å. All Pu(2)-Ni(1) bond lengths are 2.95 Å. All Pu(2)-Ni(3) bond lengths are 3.11 Å. All Pu(2)-Ni(4) bond lengths are 3.02 Å. There are four inequivalent Ni sites. In the first Ni site, Ni(1) is bonded in a 12-coordinate geometry to one Pu(1), one Pu(2), two equivalent Ni(1), two equivalent Ni(2), two equivalent Ni(3), and four equivalent Ni(4) atoms. There is one shorter (2.37 Å) and one longer (2.51 Å) Ni(1)-Ni(1) bond length. Both Ni(1)-Ni(2) bond lengths are 2.72 Å. Both Ni(1)-Ni(3) bond lengths are 2.38 Å. There are two shorter (2.48 Å) and two longer (2.49 Å) Ni(1)-Ni(4) bond lengths. In the second Ni site, Ni(2) is bonded in a 14-coordinate geometry to one Pu(2), one Ni(2), three equivalent Ni(3), three equivalent Ni(4), and six equivalent Ni(1) atoms. The Ni(2)-Ni(2) bond length is 2.40 Å. All Ni(2)-Ni(3) bond lengths are 2.51 Å. All Ni(2)-Ni(4) bond lengths are 2.59 Å. In the third Ni site, Ni(3) is bonded to two equivalent Pu(2), two equivalent Ni(2), four equivalent Ni(1), and four equivalent Ni(4) atoms to form NiPu2Ni10 cuboctahedra that share corners with four equivalent Ni(3)Pu2Ni10 cuboctahedra, corners with ten equivalent Ni(4)Pu3Ni9 cuboctahedra, edges with six equivalent Ni(4)Pu3Ni9 cuboctahedra, faces with four equivalent Ni(4)Pu3Ni9 cuboctahedra, and faces with six equivalent Ni(3)Pu2Ni10 cuboctahedra. All Ni(3)-Ni(4) bond lengths are 2.40 Å. In the fourth Ni site, Ni(4) is bonded to one Pu(2), two equivalent Pu(1), one Ni(2), two equivalent Ni(3), two equivalent Ni(4), and four equivalent Ni(1) atoms to form distorted NiPu3Ni9 cuboctahedra that share corners with five equivalent Ni(3)Pu2Ni10 cuboctahedra, corners with ten equivalent Ni(4)Pu3Ni9 cuboctahedra, edges with three equivalent Ni(3)Pu2Ni10 cuboctahedra, edges with five equivalent Ni(4)Pu3Ni9 cuboctahedra, faces with two equivalent Ni(3)Pu2Ni10 cuboctahedra, and faces with eight equivalent Ni(4)Pu3Ni9 cuboctahedra. Both Ni(4)-Ni(4) bond lengths are 2.39 Å.