Dynamics of vibrational dissociation of a pseudo-cluster

Abstract

In the context of studying phenomena, such as photodissociation of molecules and biomo-lecular reactions with methods developed in the theory of classical dynamical systems, a variety of the underlying coupled or driven nonlinear oscillator models rely on the use of the Morse oscillator as a main ingredient. These models are mostly Hamiltonian model systems with at least two-degrees-of-freedom based on several assumptions as to the form of the coupling [1],[2], [3],[4],[5], [6]. The model underlying the present study belongs to this category. Its choice was partly motivated by the kicked-oscillator model of ref. [7], in which the strength of the kick was chosen to be proportional to the Morse potential itself. In a sense, our model which merely couples a harmonic oscillator to a Morse potential in a specific way (see Eq. (3)) provides the complimentary autonomous counterpart of the time dependent system studied in [7]. It is a simple model for unimolecular fragmentation, e.g. of a cluster consisting of an atom weakly bound to a polyatomic molecule, the intramolecular dynamics of which being reduced to just one effective harmonic oscillator, responsible for transferring energy to the van der Waals (vdW) bond. We may call this fictitious system a pseudo-cluster.