RESUMEN
In the atmosphere, the photodissociation of HONO is a significant source of OH radicals after ozone. In the present study, using Born-Oppenheimer molecular dynamics, we showed that HONO can dissociate on ice and water surfaces without light. In addition, the dissociation time of HONO is found to be much less on the ice surface compared to the same time on the water droplets.
RESUMEN
In the present work, we have studied the N2O + O(1D,3P) reaction using high level quantum chemical calculations along with non-adiabatic kinetics. For quantum chemical calculations, we used the post-CCSD(T) method, which includes corrections from full triple excitations and partial quadratic excitations at the coupled-cluster level. For both the paths (N2 + O2 and 2NO), we have computed the rate constants over a wide range of temperatures (100-500 K for singlet paths and 700-4000 K for triplet paths). To assess the accuracy of our computations, we have compared our results with various experimentally measured quantities (absolute rate constant, branching fraction, and crossover temperature) and found a good match with all of them. We recommend the Arrhenius expressions for singlet paths, which turn out to be 4.46 × 10-11 exp(0.022/RT) cm3 molecule-1 s-1 and 7.12 × 10-11 exp(0.024/RT) cm3 molecule-1 s-1 for N2 + O2 and NO paths, respectively. For triplet paths, our recommended Arrhenius expressions are 5.15 × 10-12 exp(-15.35/RT) cm3 molecule-1 s-1 and 1.59 × 10-10 exp(-27.76/RT) cm3 molecule-1 s-1 for N2 + O2 and NO paths, respectively.