Optical absorption of silver clusters: A study of the effective potential core size

We study the effects of the core size of an effective pseudopotential on the determination of the absorption spectra of Agn (n = 4–22) clusters. In particular, we debate over whether 4s and 4p semicore electrons should be treated as core or valence electrons in the framework of the time-dependent density functional theory. The present study shows that the use of a small-core is suitable for the calculation of excited states for large clusters and to describe their electronic nature.