Electronic polarization effects play an important role in the interactions
of charged species in biologically relevant aqueous solutions, such as those involving salt
ions, proteins, nucleic acids, or phospholipid membranes. Explicit inclusion of electronic
polarization in molecular modeling is tedious both from the point of view of force field
parametrization and actual performance of the simulations. Therefore, the vast majority
of biomolecular simulations is performed using nonpolarizable force fields, which can
lead to artifacts such as dramatically overestimated ion pairing, particularly when
polyvalent ions are involved. Here, we show that many of these issues can be remedied
without extra computational costs by including electronic polarization in a mean field
way via charge rescaling. We also lay the solid physical foundations of this approach and
reconcile from this perspective the microscopic versus macroscopic natures of
nonpolarizable force fields.