Long timescale dynamics of shocked nitromethane

We present the farthest ever glimpse behind the shock front in a chemically reactive molecular dynamics simulation by applying a multi-scale shock wave simulation technique to the study of chemical reactions in shocked nitromethane (CH3NO2) represented by the DFTB tightbinding method. Shock speeds from 5.5 km/s to 8 km/s are simulated for durations up to 0.8 ns demonstrating substantial computational savings compared with the non-equilibrium molecular dynamics (NEMD)shock simulation approach. These simulations indicate that the reaction zone in detonating nitromethane is greater than 0.3 $\mu$m in length. Ionic species are found to be prevalent in the early reactions of shocked nitromethane. Results are consistent with available experimental data. As a validation of our multiscale approach, we compare spatial wave profiles computed with the multiscale technique to profiles computed using the NEMD approach.