PARALLEL REPLICA METHOD FOR DYNAMICS OF INFREQUENT EVENTS

Although molecular-dynamics simulations can be parallelized effectivel y to treat large systems (10(6)-10(8) atoms), to date the power of par allel computers has not been harnessed to make analogous gains in time scale. I present a simple approach for infrequent-event systems that extends the time scale with high parallel efficiency. Integrating a re plica of the system independently on each processor until the first tr ansition occurs gives the correct transition-time distribution, and he nce the correct dynamics. I obtain >90% efficiency simulating Cu(100) surface vacancy diffusion on 15 processors.