Temperature-accelerated dynamics for simulation of infrequent events

We present a method for accelerating dynamic simulations of activated proce sses in solids. By raising the temperature, but allowing only those events that should occur at the original temperature, the time scale of a simulati on is extended by orders of magnitude compared to ordinary molecular dynami cs, while preserving the correct dynamics at the original temperature. The main assumption behind the method is harmonic transition state theory. Impo rtantly, the method does not require any prior knowledge about the transiti on mechanisms. As an example, the method is applied to a study of surface d iffusion, where concerted processes play a key role. In the example, times of hours are achieved at a temperature of 150 K. (C) 2000 American Institut e of Physics. [S0021-9606(00)70618-0].