Abstract
An accelerated atomistic kinetic Monte Carlo (KMC) approach for evolving complex atomistic structures has been developed. The method incorporates on-the-fly calculations of transition states with a new scheme for defining active volumes in an off-lattice (relaxed) system. In contrast to conventional KMC models that require all reactions to be predetermined, the new approach is self-evolving and any physically relevant motion or reaction may occur. Application of this self-evolving atomistic kinetic Monte Carlo (SEAK-MC) approach is illustrated by predicting the evolution of a complex defect configuration obtained in a molecular dynamics (MD) simulation of a displacement cascade in Fe. Over much longer times, it was shown that interstitial clusters interacting with other defects may change their structure, e.g. from glissile to sessile configuration. The direct comparison with MD modeling confirms the atomistic fidelity of the new approach, while the longer time simulation demonstrates the new capability of the model.
