Dynamics Study of Intramolecular Vibrational Energy Redistribution in RDX Molecule

In this paper,based on the Born-oppenheimer molecular dynamics(BOMD) simulations,the coupling matrix between different vibrational modes of cyclotrimethylene trinitramine(RDX)single molecule was constructed, and the optimal energy transfer pathways from low-frequency vibrational mode to high-frequency vibrational mode with different initiation energies were obtained. The results showed that the -NNO2 group in RDX single molecule was more favorable for energy localization,while vibrational mode v3 and vibrational mode v4 played an important role in the energy transfer process from low-frequency vibrational mode to high-frequency vibrational mode. The further analysis for the two vibrational modes of v3 and v4 suggested that different initiation energy could lead to different energy transfer pathways for RDX single molecule. With the lower initiation energy,the RDX single molecule tended to follow the energy transfer pathway as,low-frequency vibrational mode. medium-frequency vibrational mode. high-frequency vibrational mode. With the higher initiation energy,the energy tended to transfer from the low-frequency vibrational mode to the high-frequency vibrational mode. This work reveals the detail mechanism of the intramolecular vibrational energy redistribution in single RDX molecule,and can be further applied in the investiga. tion of other energy transfer process.