Authors: A.I. Shestakov, J.L. Milovich and A. Noy
Affilation: Lawrence Livermore National Laboratory, United States
Pages: 39 - 43
Keywords: Poisson-Boltzmann, chemical force microscopy, pseudo transient continuation, finite elements
The nonlinear Poisson-Boltzmann (PB) eequation is solved using Pseudo Transient Continuation. The PB solver is constructed by modifying the nonlinear diffusion modeule of a 3D, massively parallel, unstructured grid, finite element, radiation-hydrodynamics code. The solver also computes the electrostatic energy and evaluates the force on a user-specified contour. Either Dirichlet or mixed boundary conditions are allowed. The latter specifies surface charges, approximates far-field conditions, or lineariezes conditions "regulating" the surface charge. The code may be run in either Cartesian, cylindrical, or spherical coordinates. THe potential and force due to a conical probe interacting with a flat plate is computed and the result compared with direct force measurements by chemical force microscopy.