First-principles isomer-specific absorption spectra ofAg11

Abstract

The atomic structures, static polarizabilities, and optical absorption spectra of eight low-energy isomers of ${\mathrm{Ag}}_{11}$ are investigated from first principles within static and time-dependent density functional theory. The energies of all eight fall within a range of $\ensuremath{\sim}0.3\phantom{\rule{0.3em}{0ex}}\mathrm{eV}$ in width. It is the spectrum of the lowest-energy isomer that exhibits the best overall agreement with the available measured spectra. The analysis indicates that the $d$ electrons play an important role in the optical excitations of ${\mathrm{Ag}}_{11}$; the degree of their contribution to the spectra is larger than that found in smaller silver clusters.