PuNi4 crystallizes in the monoclinic C2/m space group. There are two inequivalent Pu sites. In the first Pu site, Pu(1) is bonded in a 14-coordinate geometry to two equivalent Ni(2), four equivalent Ni(1), and eight equivalent Ni(4) atoms. In the second Pu site, Pu(2) is bonded in a distorted hexagonal planar geometry to four equivalent Ni(2), six equivalent Ni(3), and eight equivalent Ni(1) atoms. There are four inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to two equivalent Pu(1), two equivalent Pu(2), two equivalent Ni(1), two equivalent Ni(2), two equivalent Ni(3), and two equivalent Ni(4) atoms to form a mixture of edge, face, and corner-sharing NiPu4Ni8 cuboctahedra. In the second Ni site, Ni(2) is bonded to two equivalent Pu(1), two equivalent Pu(2), two equivalent Ni(3), two equivalent Ni(4), and four equivalent Ni(1) atoms to form a mixture of edge, face, and corner-sharing NiPu4Ni8 cuboctahedra. In the third Ni site, Ni(3) is bonded in a 12-coordinate geometry to three equivalent Pu(2), two equivalent Ni(2), three equivalent Ni(3), and four equivalent Ni(1) atoms. In the fourth Ni site, Ni(4) is bonded in a 12-coordinate geometry to four equivalent Pu(1), one Ni(2), two equivalent Ni(1), and five equivalent Ni(4) atoms.
PuNi4 crystallizes in the monoclinic C2/m space group. There are two inequivalent Pu sites. In the first Pu site, Pu(1) is bonded in a 14-coordinate geometry to two equivalent Ni(2), four equivalent Ni(1), and eight equivalent Ni(4) atoms. There is one shorter (2.87 Å) and one longer (2.91 Å) Pu(1)-Ni(2) bond length. There are two shorter (2.89 Å) and two longer (2.91 Å) Pu(1)-Ni(1) bond lengths. There are a spread of Pu(1)-Ni(4) bond distances ranging from 2.82-2.91 Å. In the second Pu site, Pu(2) is bonded in a distorted hexagonal planar geometry to four equivalent Ni(2), six equivalent Ni(3), and eight equivalent Ni(1) atoms. There are two shorter (3.16 Å) and two longer (3.17 Å) Pu(2)-Ni(2) bond lengths. There are four shorter (2.81 Å) and two longer (2.83 Å) Pu(2)-Ni(3) bond lengths. There are four shorter (3.14 Å) and four longer (3.15 Å) Pu(2)-Ni(1) bond lengths. There are four inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to two equivalent Pu(1), two equivalent Pu(2), two equivalent Ni(1), two equivalent Ni(2), two equivalent Ni(3), and two equivalent Ni(4) atoms to form a mixture of edge, face, and corner-sharing NiPu4Ni8 cuboctahedra. Both Ni(1)-Ni(1) bond lengths are 2.44 Å. There is one shorter (2.43 Å) and one longer (2.44 Å) Ni(1)-Ni(2) bond length. Both Ni(1)-Ni(3) bond lengths are 2.44 Å. There is one shorter (2.49 Å) and one longer (2.50 Å) Ni(1)-Ni(4) bond length. In the second Ni site, Ni(2) is bonded to two equivalent Pu(1), two equivalent Pu(2), two equivalent Ni(3), two equivalent Ni(4), and four equivalent Ni(1) atoms to form a mixture of edge, face, and corner-sharing NiPu4Ni8 cuboctahedra. Both Ni(2)-Ni(3) bond lengths are 2.45 Å. Both Ni(2)-Ni(4) bond lengths are 2.50 Å. In the third Ni site, Ni(3) is bonded in a 12-coordinate geometry to three equivalent Pu(2), two equivalent Ni(2), three equivalent Ni(3), and four equivalent Ni(1) atoms. There is one shorter (2.79 Å) and two longer (2.83 Å) Ni(3)-Ni(3) bond lengths. In the fourth Ni site, Ni(4) is bonded in a 12-coordinate geometry to four equivalent Pu(1), one Ni(2), two equivalent Ni(1), and five equivalent Ni(4) atoms. There are a spread of Ni(4)-Ni(4) bond distances ranging from 2.45-2.88 Å.