In order to obtain accurate spectra, snapshots from the QM/MM MD equilibrated trajectory are extracted, and the environment composed of protein chains, lipid bilayer, water, and ions of solvation will be considered polarizable. Unlike in electrostatic embedding, where the QM and MM subsystems interact through point charges, in more advanced polarizable models like in Polarizable Embedding (PE), the environment is described by atomic distributed multipoles (static and induced) and polarizabilities. Static multipoles describe the static charge distribution of the environment, while polarizabilities generate induced dipoles in response to the fields emanating from the electrons and nuclei in the QM subsystem, as well as from both the static multiples and induced dipoles from the rest of the atoms of the environment. This approach ensures a self-consistent description of the polarization. 62,63