Decomposition Mechanism Studies of Energetic Molecules Using HOMO and LUMO Orbital Energy Driven Molecular Dynamics

In this paper, we present decomposition mechanism studies of energetic molecules using HOMO and LUMO orbital energy gap driven molecular dynamics (MD) method. Under frozen orbital approximation, this is an ‘electronic excitation’ MD, where electrons is excited from HOMO to LUMO orbitals Meanwhile, the HOMO and LUMO orbital energy gap is taken as a biasing potential to accelerate chemical reactions, in particular for electronic excitation due to external stimulating, such as high temperature and high pressure in shock wave detonation. We applied this method on decomposition reaction simulations on 1,3,5,7‐tetranitro‐1,3,5,7‐tetrazocane (HMX) and 1,3,5‐trinitro‐1,3,5‐triazacyclohexane (RDX) energetic molecules. It shows that the cleavage of the N‐N bond appears as the principle event in the decomposition when electrons are excited.