Modelling environment effects on spectroscopic molecular responses with hybrid QM/classical methods

The objective of this work is the accurate modelling of environment effects, i.e. the modifications in the properties and the processes of molecular systems when interacting with an environment, using hybrid Quantum Mechanical/classical methods. In particular, the focus is on the changes induced by the environment on electronic transitions (both in absorption and in the emission processes), vibrational transitions and vibrational couplings. The hybrid QM/classical methods used introduce either an atomistic or a continuum description for the classical part of the system but in both cases mutual polarization effects between the QM and the classical subsystems are included. These methods have been applied to environments of increasing complexity going from isotropic solvents to lipid bilayers and DNA fragments.