Poisson-Nernst-Planck (PNP) electrodiffusion theory

Electrodiffusion theory is a useful approach to describe the flow of ions through aqueous channels. The PNP theory is based on a mean-field continuum electrostatic approximation. The theory solves self-consistently for the non-equilibrium ion density (from Fick's law) and the electrostatic potential (from Poisson's equation). It is valid only for fairly wide aqueous pores. The results from three-dimensional (3d) PNP have been compared to those from the GCMC/BD algorithm in the case of the OmpF porin from E. coli