Mixed Atomistic-Implicit Quantum/Classical Approach to Molecular Nanoplasmonics

Abstract

A multiscale QM/classical approach is presented, that is able to model the optical properties of complex nanostructures composed of a molecular system adsorbed on metal nanoparticles. The latter are described by a combined atomistic-continuum model, where the core is described using the implicit boundary element method (BEM) and the surface retains a fully atomistic picture and is treated employing the frequency-dependent fluctuating charge and fluctuating dipole ($\ddot{I}‰$FQF$\hat{I}¼$) approach. The integrated QM/$\ddot{I}‰$FQF$\hat{I}¼$-BEM model is numerically compared with state-of-the-art fully atomistic approaches, and the quality of the continuum/core partition is evaluated. The method is then extended to compute Surface-Enhanced Raman Scattering (SERS) within a Time-Dependent Density Functional Theory (TDDFT) framework.

12 pages, 5 figures, 2 tables