HYPERDYNAMICS - ACCELERATED MOLECULAR-DYNAMICS OF INFREQUENT EVENTS

I derive a general method for accelerating the molecular-dynamics (MD) simulation of infrequent events in solids. A bias potential (Delta V- b) raises the energy in regions other than the transition states b bet ween potential basins. Transitions occur at an accelerated rate and th e elapsed time becomes a statistical property of the system. Delta V-b can be constructed without knowing the location of the transition sta tes and implementation requires only first derivatives. I examine the diffusion mechanisms of a 10-atom Ag cluster on the Ag(111) surface us ing a 220 mu s hyper-MD simulation.