Simulation of RDX Decomposition Interacting with Shock Wave via Molecular Dynamics

Cylotrimethylenetrinitramine (RDX), with the chemical formula C3H6N6O6, is an energetic organic molecule used widely in military and industrial commodities of explosives. By stimulating RDX through exerting temperature or mechanical conditions such as impact or friction, decomposition reaction occurs at a very high rate. Molecular dynamics techniques and LAMMPS code with Reactive Force Field (ReaxFF) potential were employed to simulate initiation of RDX. Potential energy variations of the system were calculated over time for five different temperatures up to 100 ps. The products of decomposed system with respect to time were calculated at each stage of stimulation for different values of temperature and thermal initiation stimulation energy in NVT and NVE ensembles. The activation energy of decomposition was calculated 20.230 kcal.mol-1 through Arrhenius equation. The minimum required temperature to produce H2 with temperature decomposition was about 2500 K and production times for several conditions were calculated. The amount of nitrogen and hydrogen production were increased with raising temperature and reached the maximum value at 3000 K. The minimum impetus energy required to form the light species H2 is 66 kcal.mol-1.`