Solutions of Poissonʹs equation in channel-like geometries Original Research Article

Electric forces play a key role in the conductance of ions in biological channels. Therefore, their correct treatment is very important in making physical models of ion channels. Here, we present FORTRAN 90 codes for solution of Poissonʹs equation satisfying the Dirichlet boundary conditions in realistic channel geometries that can be used in studies of ion channels. For a general channel shape, we discuss a numerical solution of Poissonʹs equation based on an iterative technique. We also provide an analytical solution of Poissonʹs equation in toroidal coordinates and its numerical implementation. A torus shaped channel is closer to reality than a cylindrical one, hence it could serve as a useful test model.