UV-visible absorption spectra of metallic clusters from TDDFT calculations

Absorption spectra of both pure silver or nickel clusters (Ag-n, n = 6-55, Ni-p, p = 8-12) and mixed silver-nickel clusters (AgnNin, n = 3-6) are investigated in the framework of the time-dependent density functional theory (TDDFT) with the use of the functional CAM-B3LYP. The spectra of silver nickel clusters are compared to those of pure silver and nickel clusters. An interpretation of spectroscopic patterns in terms of contribution from s- and d-type excitations is presented. In particular the d electrons of nickel atoms are found to play a crucial role in the optical transitions in Ni-rich systems.