Pairwise solute descreening of solute charges from a dielectric medium

We present an algorithm for incorporating a pairwise descreening approximation into the calculation of the electrostatic component of the polarization free energy of solvation within the generalized Born approximation. The method was tested on a set of 139 molecules containing H, C, O, and N. The complexity of the descreening calculation is greatly simplified by the pairwise approximation; nevertheless, using the pairwise descreening method to parameterize a new version of a previous generalized Born solvation model, we found that the rms error relative to experiment increased by only 0.2 kcal/mol.