Time Evolution of Plasmonic Features in Pentagonal Ag Clusters

In the present work, we apply recently developed real-time descriptors to study the time evolution of plasmonic features of pentagonal Ag clusters. The method is based on the propagation of the time-dependent Schrodinger equation within a singly excited TDDFT ansatz. We use transition contribution maps (TCMs) and induced density to characterize the optical longitudinal and transverse response of such clusters, when interacting with pulses resonant with the low-energy (around 2-3 eV, A(1)) size-dependent or the high-energy (around 4 eV, E-1) size-independent peak. TCMs plots on the analyzed clusters, Ag-25(+) and Ag-43(+) show off-diagonal peaks consistent with a plasmonic response when a longitudinal pulse resonant at A(1) frequency is applied, and dominant diagonal spots, typical of a molecular transition, when a transverse E-1 pulse is employed. Induced densities confirm this behavior, with a dipole-like charge distribution in the first case. The optical features show a time delay with respect to the evolution of the external pulse, consistent with those found in the literature for real-time TDDFT calculations on metal clusters.

Automated summary

In this study, recently developed real-time descriptors are applied to investigate the time evolution of plasmonic features of pentagonal Ag clusters. The method involves the propagation of the time-dependent Schrodinger equation using a singly excited TDDFT ansatz. Transition contribution maps (TCMs) and induced density are used to characterize the optical response of the clusters when interacting with resonant pulses at different energy levels. The results demonstrate a plasmonic response when a longitudinal pulse is applied and a molecular transition when a transverse pulse is employed, which are confirmed by the induced charge distributions.