Quasi-Classical Trajectory Method to study the molecular semi-collision of Ne79 Br2 (X, B)

Dynamical calculations are ideally desired to give the most detailed information on final state distributions in collision or semi-collision processes. In this regard, it is often the case that practical inconveniences severely restrict the application of the intrinsically accurate quantum calculations, which is particularly a problem if large clusters are to be studied. In most cases, however, the quasi-classical methods exhibit a relatively high interpretative power/computational cost ratio and allow the full dimensionality of the system to be included. Nevertheless, although quasi-classical calculations are important for constructing intuitive models on molecular processes, the limits of their validity and applicability remain uncertain. During the last two decades, the Ne79 Br2 van der Waals complex has been the subject of intensive investigation from both the experimental and theoretical points of view [1]. In this work, we show how a very good description of the available data [2] can be achieved by performing a full-dimensional quasi-classical trajectories study on the process in both electronic molecular states (X and B). The influence of two quantum effects (the closing of the Delta v' = -1 dissociation channel and the intramolecular vibrational relaxation (IVR) mechanism) on the agreement with experimental rotational distributions, is analysed. A discussion on the viability of similar quasi-classical methods to model the VP dynamics of analogous clusters is presented, along with the relevance of the binning procedure to employ when extracting quantum from classical distributions. [1] M. L. Gonzalez-Martinez, J. Rubayo-Soneira and K. Janda, Phys. Chem. Chem. Phys. 39, 4550 (2006). [2] See, for example: M. Nejad-Sattari and T. A. Stephenson, J. Chem. Phys. 106, 5454 (1997) and J. A. Cabrera, C. R. Bieler, B. C. Olbricht, W. E. van der Veer and K. C. Janda, J. Chem. Phys. 123, 054311 (2005)