Simulating the unimolecular decomposition pathways of cyclotrimethylnitramine (RDX)

Based on the three known proposed pathways for the uni-molecular decomposition of RDX, we have formulated the rate equations. A kinetic Monte Carlo code has been developed and used to simulate the uni-molecular decomposition of RDX based on these equations. The KMC simulations allow one to explore each of the decomposition pathways individually and also the three competing pathways at a specified temperature and pressure. The pressure dependence is incorporated using Lindemann's formalism. The code is validated by reproducing the species evolution along each pathway. Amongst the three proposed pathways, the most likely path of RDX decomposition and the time evolution of various molecular species at different ambient temperatures and pressures are obtained. An analytical model has been developed to reproduce the decomposition pathways, which matches the simulation results.