A smooth permittivity function for Poisson-Boltzmann solvation methods

This work introduces a continuous smooth permittivity function into Poisson-Boltzmann techniques for continuum approaches to modeling the solvation of small molecules and proteins. The permittivity function is derived using a Gaussian method to describe volume exclusion. The new method allows a rigorous determination of solvent forces within a grid-based technology. The generality of approach is demonstrated by considering a range of applications for small molecules and macromolecules. We also present a very complete statistical analysis of grid errors, and show that the accuracy of our Gaussian-based method is improved over standard techniques. The method has been implemented in a new code called ZAP, which is freely available to academic institutions.(1) (C) 2001 John Wiley & Sons, Inc.