Nitric predissociation

Molecular dynamics studies of diatomic model detonations were first carried out by Karo and Hardy in 1977 [14]. They were soon followed by other groups [15, 16]. These early studies employed predissociative potentials, in which the reactant dimer molecules are metastable and can dissociate exothermically. More realistic models, combining an endothermic dissociation of reactants with an exothermic formation of product molecules, were introduced by White and colleagues at the Naval Research Laboratory and U.S. Naval Academy, first using a LEPS (London-Eyring-Polanyi-Sato) three-body potential for nitric oxide [17], and later a Tersoff-type bond-order potential [18] for a generic AB model, loosely based on NO [19, 20]. 

Calculation of the photolysis rate of nitric oxide must include the predissociation process which occurs at wavelengths less than 192 nm. In particular, predissociation occurs (Figure 4.43) in the 5 bands, the (3 bands (v > 6) and the e bands (v > 3). Callear and Pilling (1970 a,b) indicate that emission dominates predissociation in the e bands. At zero optical depth, the contribution of the 7 bands is small compared to those of the 5 and / bands. 

Callear, A.B., Pilling, M.J. Fluorescence of nitric oxide. Part 7. -Quenching rates of NO n(v = 0), its rate of radiation to NO A S+, energy transfer efficiencies, and mechanisms of predissociation. Trans. Faraday Soc. 66, 1618-1634 (1970)... 

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