DETERMINATION OF ATOMIC CHARGES INCLUDING SOLVATION AND CONFORMATIONAL EFFECTS

We present a method to calculate the charge redistribution that occurs during ionophore potential of mean force (PMF) calculations. A new charge distribution is calculated at the beginning of each simulation that is used to assemble the PMF energy profile. This charge distribution reflects the environment of the ionophore (i.e., the proximity of the ion and solvent) and we have tested this method on the association of K+ with 18-crown-6 in methanol. The charges of the oxygens that bind the ion become less negative as the ion is discharged from the complex. We have compared the PMF profile obtained from this method to two PMF profiles obtained using fixed charge models.