The rate constants are calculated using the species evolution of RDX molecules in 10 ps. The rate constant derived from the NNP is in the same order as the ReaxFF model but higher by a factor of two. From the Arrhenius plot in Fig. , Arrhenius parameters for RDX decomposition are determined by a direct fitting. The activation energies predicted by NNP and ReaxFF are 25.24 and 26.01 kcal/mol, respectively. The results from both models are in good agreement with the experimental value of 28.6 kcal/mol using the Kissinger method . The above discussion confirms that the NNP accurately describes the kinetics of RDX decomposition. In the following section, we discuss the detailed decomposition mechanism of RDX crystal from condensed phase into gas-phase intermediates.