DFT investigation on the SERS band at ∼1025 cm−1 of pyridine adsorbed on silver

A conclusive study on the SERS band of pyridine occurring at about 1025 cm−1 was performed by a density functional theory (DFT) approach, by considering the ligand molecules bound to silver adclusters. The existence of (Ag3)+2 surface active-sites, ascertained in Ag/SiO2 colloids as metal adclusters stabilised by the interaction with the silica nanoparticles, was confirmed by DFT calculations, which satisfactorily account for the experimental findings.