There have been some attempts to address these issues; particularly, both instantaneous and post-simulation correction strategies have been proposed . One approach is to apply various after-the-fact corrections to computed free energies . Alternatively, others have proposed applying a correction strategy during simulations, which has been called a co-alchemical ion approach, wherein an alchemical perturbation of a charged moiety is simultaneously performed with a counter-alchemical charge perturbation of a remote molecule (i.e. a counter-ion) . In other words, in this approach, the system is maintained net neutral by offsetting a charge change in one portion of a system with a compensating change in another portion of the system. The goal in this approach is to ensure that errors from finite-size effects are negligible. Post simulation strategies include charge-correction terms which have been shown to work for LS and RF, and can be evaluated via numerical and analytical methods .