Determination of the lowest-energy structure of Ag 8 from first-principles calculations

The ground-state electronic and structural properties and the electronic excitations of the lowest-energy isomers of the Ag{sub 8} cluster are calculated using density functional theory (DFT) and time-dependent DFT (TDDFT) in real-time and real-space schemes, respectively. The optical spectra provided by TDDFT predict that the D{sub 2d} dodecahedron isomer is the structural minimum of the Ag{sub 8} cluster. Indeed, it is borne out by the experimental findings.