Enabling Computational Nanotechnology through JavaGenes in a Cycle Scavenging Environment

Abstract: A genetic algorithm procedure is developed and implemented for fitting parameters for many-body inter-atomic force field functions for simulating nanotechnology atomistic applications using portable Java on cycle-scavenged heterogeneous workstations. Given a physics based analytic functional form for the force field, correlated parameters in a multi-dimensional environment are typically chosen to fit properties given either by experiments and/or by higher accuracy quantum mechanical simulations. The implementation automates this tedious procedure using an evolutionary computing algorithm operating on hundreds of cycle-scavenged computers. As a proof of concept, we demonstrate the procedure for evaluating the Stillinger-Weber (S-W) potential by (a) reproducing the published parameters for Si using S-W energies in the fitness function, and (b) evolving a “new ” set of parameters using semi-empirical tightbinding energies in the fitness function. The “new ” parameters are significantly better suited for Si cluster energies and forces as compared to even the published S-W potential. 1. Introduction: Accurate molecular dynamics (MD) simulation of reactive systems containing many atomic species is important for the conceptualization, design and testin