Effect of pressure on nitramine dissociation: A density-functional theory study*

The effect of increased pressure on the initial pathways and kinetics of dimethylnitramine dissociation is studied using density-functional theory (DFT). Two competitive pathways, radical NO$_2$ elimination and concerted HONO elimination, are evaluated using atomic basis, hybrid DFT thermochemistry and planewave DFT molecular dynamics. The computed thermochemistry and reactive dynamics of condensed-phase dissociation are contrasted with those in the gas phase. These results are discussed in the context of developing a reduced chemical model of nitramine decomposition suitable for inclusion in mesoscale simulations.