A discrete interaction model/quantum mechanical method for simulating surface-enhanced Raman spectroscopy
| العنوان: | A discrete interaction model/quantum mechanical method for simulating surface-enhanced Raman spectroscopy |
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| المؤلفون: | Seth M. Morton, John L. Payton, Lasse Jensen, Justin E. Moore |
| المصدر: | The Journal of Chemical Physics. 136:214103 |
| بيانات النشر: | AIP Publishing, 2012. |
| سنة النشر: | 2012 |
| مصطلحات موضوعية: | Chemistry, General Physics and Astronomy, Nanoparticle, Time-dependent density functional theory, Surface-enhanced Raman spectroscopy, Molecular physics, symbols.namesake, Quantum mechanics, symbols, Density functional theory, Physical and Theoretical Chemistry, Raman spectroscopy, Local field, Plasmon, Raman scattering |
| الوصف: | We have derived and implemented analytical gradients for the discrete interaction model/quantum mechanics (DIM/QM) method. DIM/QM combines an atomistic electrodynamics model with time-dependent density functional theory and thus enables modeling of the optical properties for a molecule while taking into account the local environment of a nanoparticle's surface. The DIM/QM analytical gradients allow for geometry optimizations, vibrational frequencies, and Raman spectra to be simulated for molecules interacting with metal nanoparticles. We have simulated the surface-enhanced Raman scattering (SERS) spectra for pyridine adsorbed on different sites of icosahedral nanoparticles with diameters between 1 and 8 nm. To describe the adsorption of the pyridine molecule onto the metal surface, we have implemented a coordination-dependent force field to differentiate the various local surface environments. We find that the DIM/QM method predicts geometries and frequencies that are in good agreement with full QM simulations and experiments. For the simulated SERS spectra of pyridine, we find a significant dependence on the adsorption site and the size of the metal nanoparticle. This illustrates the importance of accounting for the local environment around the molecule. The Raman enhancement factors are shown to roughly mirror the magnitude of the nanoparticle's local field about the molecule. Because the simulated nanoparticles are small, the plasmon peaks are quite broad which results in weak local electric fields and thus modest Raman enhancement factors. |
| تدمد: | 1089-7690 0021-9606 |
| URL الوصول: | https://explore.openaire.eu/search/publication?articleId=doi_dedup___::e75370bda5e3e9dc709c3f9e2fe959e2 https://doi.org/10.1063/1.4722755 |
| رقم الأكسشن: | edsair.doi.dedup.....e75370bda5e3e9dc709c3f9e2fe959e2 |
| قاعدة البيانات: | OpenAIRE |
Find this article in full text from Scitation. | تدمد: | 10897690 00219606 |
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