Elucidating Long Timescale Chemical Events in Reactive Materials

Knowledge of the equation of state and chemical kinetics of materials under reactive conditions is needed for a wide number of research areas, including studies of planetary interiors, astrobiology, and high-pressure detonations of energetic materials. In this regard, we have developed a family of atomistic simulation models which yield similar accuracy to higher order quantum approaches (Kohn-Sham DFT) while yielding orders of magnitude increase in computational efficiency. This talk will focus on three different types of models in development in our research group: (1) semi-empirical quantum simulation approaches, (2) reactive force fields for molecular dynamics simulations, and (3) spin lattice models for solid phase reactivity. These efforts will be discussed in the context of corrosion on actinide and other metal surfaces, shock compression of organics and energetic materials, and prebiotic synthesis in impacting astrophysical ices. Our methods provide a straightforward way to conduct computationally efficient and highly accurate simulations over a broad range of conditions, where physical and chemical properties can be difficult to interrogate directly and there is historically a significant reliance on theoretical approaches for interpretation and validation of experimental results. Prepared by LLNL under Contract DE-AC52-07NA27344