Optical excitations of gold nanoparticles: A quantum chemical scalar relativistic time dependent density functional study

The valence optical excitation spectra of the gold clusters series Au-6(4+), Au-44(4+), and Au-146(2+) have been calculated at the scalar relativistic time dependent density functional theory level. Optical spectra have been calculated at the optimized geometries, the electronic structure has been described in terms of density of states, and optical spectra have been discussed in terms of electronic structure features. The well-known blue shift with decreasing cluster size has been successfully predicted by the theory.