It was noted that many interesting long-term dynamic properties of solid interfaces, such as deep diffusion, pervasion and phase-forming, could not be simulated directly using traditional molecular dynamics because of nanosecond timescale limitations. Thus, a simpler bias potential form was proposed within the Voter hyper-dynamics scheme. In this method, the potential energy wells were raised by adding a coefficient, defined as an accelerating factor, to the original potential. The escape rate from potential wells was thus enhanced, and extended the timescale by several orders of magnitude as compared to traditional simulations. More importantly, the features of the potential surface were reserved even without any in-advance knowledge of the location of either the potential energy wells or saddle points. This method was demonstrated by applying it to the mutual diffusion of atoms in the Mg/Zn interface with different accelerating factors using a simple Lennard-Jones potential. The results showed that long-time simulation could be realized very easily.

Method of Accelerating Molecular Dynamics Simulation for Atomic Diffusion in Metallic Interface. Zhang, X.M., Yang, L.H., Wu, Y.Q., Shen, T., Zheng, S.B., Jiang, G.C.: Acta Physica Sinica, 2008, 57[4], 2392-8