The spectral response of molecular probes strongly depends on the surrounding environment. A successful approach to computational spectroscopy of systems in the condensed phase consists of resorting to focused models, where the focus is on a specific portion of the system, which is described at the Quantum Mechanical (QM) level, whereas the remaining portion is treated classically, through ad-hoc Molecular Mechanics (MM) force-fields [1]. In case of solvated systems, Polarizable QM/MM approaches, where the mutual polarization between QM and MM layers is considered are particularly successful [2-10]. On the other hand, the computational spectroscopy of complex plasmonic nanostructured materials re- quires alternative approaches, which can appropriately model environments at resonance with the external probing field [11-14]. I will discuss the most recent contributions of our group in this field, by also resorting to pilot applications which highlight the methods’ potentialities.

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