Novel pseudospectral Fourier method for solving Poisson's equation for a solute in a non-uniform dielectric

A novel pseudospectral method is presented for solving Poisson's equation for a solute in a non-uniform dielectric. Poisson's equation is transformed to a Helmholtz-like equation which is solved iteratively, as a linear system of equations, by introducing a grid and employing fast Fourier transforms. Several algorithms have been rested for solution of the linear system, and application of an appropriately preconditioned linear solver has been found to provide a robust, rapidly convergent procedure. The method scales nearly linearly with system size, and its implementation is straightforward Application of the method is demonstrated for computation of the electrostatic contribution to the solvation energy for a wide range of solute molecules, and convergence of the method is shown to be nearly independent of solute and grid size. (C) 2001 Elsevier Science B.V. All rights reserved.