Plasmon Couplings from Subsystem Time-Dependent Density Functional Theory
| Autor: | Giulia Giannone, Fabio Della Sala, Stefania D'Agostino, Eduardo Fabiano, Szymon Śmiga |
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| Rok vydání: | 2021 |
| Předmět: | |
| Zdroj: | The Journal of Physical Chemistry A. 125:7246-7259 |
| ISSN: | 1520-5215 1089-5639 |
| DOI: | 10.1021/acs.jpca.1c05384 |
| Popis: | Many applications in plasmonics are related to the coupling between metallic nanoparticles (MNPs) or between an emitter and a MNP. The theoretical analysis of such a coupling is thus of fundamental importance to analyze the plasmonic behavior and to design new systems. While classical methods neglect quantum and spill-out effects, time-dependent density functional theory (TD-DFT) considers all of them and with Kohn-Sham orbitals delocalized over the whole system. Thus, within TD-DFT, no definite separation of the subsystems (the single MNP or the emitter) and their couplings is directly available. This important feature is obtained here using the subsystem formulation of TD-DFT, which has been originally developed in the context of weakly interacting organic molecules. In subsystem TD-DFT, interacting MNPs are treated independently, thus allowing us to compute the plasmon couplings directly from the subsystem TD-DFT transition densities. We show that subsystem TD-DFT, as well as a simplified version of it in which kinetic contributions are neglected, can reproduce the reference TD-DFT calculations for gap distances greater than about 6 Å or even smaller in the case of hybrid plasmonic systems (i.e., molecules interacting with MNPs). We also show that the subsystem TD-DFT can be also used as a tool to analyze the impact of charge-transfer effects. |
| Databáze: | OpenAIRE |
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