Introduction of the ReaxFF Force Field for the Simulation of Reactive Nanosystems

Experimental methods cannot describe details of the atomic and molecular processes, especially at theinterfaces. Computational classical molecular dynamic (MD) simulation techniques can provide valuable insights intosuch processes because of their ability to probe spatiotemporal atomic/molecular/nanoscale processes. However, thesetechniques fail to simulate chemical reactions. Quantum mechanical computational methods, while able to discoverdetails of a chemical reaction, cannot be used to simulate reactive systems at large length and time scales such as interfaceand diffusive-convective reactions, due to being too much time-consuming and requirement of strong hardware facilitiessometimes not available yet. In this report, we introduce a novel reactive force field (RFF), ReaxFF, developed by vanDuin et al. for the MD simulation of simple reactive systems which can be used to study chemical reactions atatomic/molecular/nano scales. Development of this RFF is based on the empirical force fields (FF) that mimic thequantum mechanical variation of bond order. The approach allows bond order and all bonded interactions to decaysmoothly to zero at large inter-atomic distances, allowing thus simulation of chemical reactions within a MD framework.Consequently, molecular dynamics simulation with RFF (RMD) can overcome many of the limitations inherent toordinary (nonreactive) MD simulation while retaining the desirable scalability.

Keywords:

reactive force field (RFF) , molecular dynamics (MD) , simulation , ReaxFF , reactive nanosystem