superatom

Superatoms are clusters of atoms that exhibit properties similar to individual atoms, particularly in their electronic structure. These clusters can possess exceptional stability due to the filling of electron shells, analogous to the stability of noble gas atoms.1

In metal clusters, this stability is determined by the electrons and their available energy states. Specific numbers of electrons, such as 8, 20, or 40, correspond to closed electron shells, leading to enhanced stability. This phenomenon can be understood by modeling the positively charged atomic cores as a uniform background and considering the behavior of the valence electrons, which are delocalized across the cluster. This electron shell structure is a key characteristic that allows these clusters to behave like larger, single atoms.1