4f electron orbitals, general set, computer model. An electron orbital is a region around an atomic nucleus (not seen) in which one or a pair of electrons is most likely to exist. The 4f orbitals are unusual in that there are two ways to represent the orbital shapes. In the general set, the bottom two orbitals are eight-lobed. The two above them have six lobes lying in a plane. The two above them are similarly planar, but the lobes on one axis are flattened. The upper orbital comprises a lobe and an equatorial cone. The cubic set is shown in image A152/166. The 4f orbitals are partially filled in the Lanthanide metals.