PuFeC2 crystallizes in the tetragonal P4/nmm space group. Pu(1) is bonded to five equivalent C(2) atoms to form a mixture of distorted edge and corner-sharing PuC5 square pyramids. Fe(1) is bonded to four equivalent C(1) atoms to form FeC4 tetrahedra that share corners with four equivalent C(2)Pu5C octahedra, corners with four equivalent Fe(1)C4 tetrahedra, and edges with four equivalent Fe(1)C4 tetrahedra. The corner-sharing octahedral tilt angles are 55°. There are two inequivalent C sites. In the first C site, C(1) is bonded in a 5-coordinate geometry to four equivalent Fe(1) and one C(2) atom. In the second C site, C(2) is bonded to five equivalent Pu(1) and one C(1) atom to form CPu5C octahedra that share corners with four equivalent C(2)Pu5C octahedra, corners with four equivalent Fe(1)C4 tetrahedra, and edges with eight equivalent C(2)Pu5C octahedra. The corner-sharing octahedral tilt angles are 14°.
PuFeC2 crystallizes in the tetragonal P4/nmm space group. Pu(1) is bonded to five equivalent C(2) atoms to form a mixture of distorted edge and corner-sharing PuC5 square pyramids. There is one shorter (2.29 Å) and four longer (2.43 Å) Pu(1)-C(2) bond lengths. Fe(1) is bonded to four equivalent C(1) atoms to form FeC4 tetrahedra that share corners with four equivalent C(2)Pu5C octahedra, corners with four equivalent Fe(1)C4 tetrahedra, and edges with four equivalent Fe(1)C4 tetrahedra. The corner-sharing octahedral tilt angles are 55°. All Fe(1)-C(1) bond lengths are 2.09 Å. There are two inequivalent C sites. In the first C site, C(1) is bonded in a 5-coordinate geometry to four equivalent Fe(1) and one C(2) atom. The C(1)-C(2) bond length is 1.46 Å. In the second C site, C(2) is bonded to five equivalent Pu(1) and one C(1) atom to form CPu5C octahedra that share corners with four equivalent C(2)Pu5C octahedra, corners with four equivalent Fe(1)C4 tetrahedra, and edges with eight equivalent C(2)Pu5C octahedra. The corner-sharing octahedral tilt angles are 14°.