Kathleen Alexander, Massachusetts Institute of Technology

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Kinetic Monte Carlo (KMC) methods have the potential to extend the accessible timescales of off-lattice atomistic simulations beyond the limits of molecular dynamics. However, it is challenging to identify the complete catalog of events accessible to an off-lattice system that is required to accurately calculate the residence time in a KMC simulation. Using a systematic approach to mapping an energy landscape, we have developed a suite of solutions to address the key challenges associated with accurately calculating residence times in off-lattice systems. We have implemented our off-lattice KMC method to study the kinetic behavior of an example grain boundary (GB) system. The results of this case study indicate that this off-lattice KMC method provides a means to study GB kinetic properties under conditions and timescales that were previously inaccessible. Toward the end of developing predictive relationships to describe GB kinetic properties across the five-parameter GB orientation space, we have used these methods to investigate whether the normalized ground state residence time of a GB is a good predictor of kinetic behavior. We see a clear relationship between normalized ground- state residence time and kinetic properties, indicating that this may be a promising characterization metric for high-throughput studies of GB properties.

Abstract Author(s): Kathleen Alexander