Triatomic molecules quantum reaction dynamics

Asymptotic analysis, electronic states, triatomic quantum reaction dynamics, 317—318 Azulene molecule, direct molecular dynamics, complete active space self-consistent field (CASSCF) technique, 408-410... 

Unimolecular dissociation is one of the simplest types of irreversible chemical reactions It takes place in a single isolated molecule with an internal energy that exceeds the first dissociation threshold see Fig. 1(a) for a schematic overview. Nevertheless, the underlying atomic-level reaction mechanisms are very complex. Their theoretical description requires all the power of modern quantum chemical methods, statistical physics and nonlinear dynamics, and even then the full rigor can be achieved just for small, mostly triatomic molecules. Experimental studies have to be likewise advanced Up to three laser pulses are combined in a modern experiment to elucidate all details of the dissociation process. 

Since nuiny processses demonstrate substantial quantum effects of tunneling, wave packet break-up and interference, and, obviously, discrete energy spectra, symmetry induced selection rules, etc., it is clearly desirable to develop meAods by which more complex dynamical problems can be solved quantum mechanically both accurately and efficiently. There is a reciprocity between the number of particles which can be treated quantum mechanically and die number of states of impcxtance. Thus the ground states of many electron systems can be determined as can the bound state (and continuum) dynamics of diatomic molecules. Our focus in this manuscript will be on nuclear dynamics of few particle systems which are not restricted to small amplitude motion. This can encompass vibrational states and isomerizations of triatomic molecules, photodissociation and exchange reactions of triatomic systems, some atom-surface collisions, etc. 

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