Photofragmentation dynamics study of ArBr $$_2$$ 2 $$(v=16,\ldots ,25)$$ ( v = 16 , … , 25 ) using two theoretical methods: trajectory surface hopping and quasiclassical trajectories

The vibrational predissociation of van der Waals complexes has been the object of study using a wide range of theoretical and experimental methods, producing a large number of results. We focus here on the ArBr $$_2$$ ( $$v=16,\ldots ,25$$ ) system. For its study, we employ two important theoretical methods: the trajectory surface hopping (TSH) and the quasiclassical trajectory method (QCTM). In the first case, the dynamics of the system are reproduced on a potential energy surface (PES) corresponding to quantum molecular vibrational states. The possibility of hopping to other vibrational surfaces is also included, which can then lead to van der Waals bond dissociation. On the other hand, the second case consists of propagating the dynamics over a single potential energy surface. We incorporate the kinetic mechanism into the TSH method for better comparison of the evolution of the complex. Both methods allow us to study the dynamical behavior of the ArBr $$_2$$ as well as several observables. We compute the lifetime, exit channel, rotational energy, and maximum angular momentum ( $$j_{max}$$ ) of Br $$_2$$ . We compare our results with previous experimental and theoretical work and also report new results for cases that have not previously been considered.