1.5-dimensional scattering barrier dynamics

A full six-dimensional PES for the HOCO system has been developed by Schatz and coworkers, particularly L. B. Harding (Kudla et al. 1992 Schatz et al. 1987). This proved to be challenging because of numerous local minima and transition states, and consequently the development of the PES has taken several years. Many points were calculated by using large scale ab initio techniques and the surface was adjusted to reconcile a broad array of experimental data such as nascent product excitations, HOCO decomposition rates, overall bimolecular reaction rates, barrier heights, enthalpy changes, HOCO structural properties, and inelastic scattering data. This PES has been used in several computational studies of the reaction dynamics that employ classical (Kudla and Schatz 1991 Kudla... 

The distinguishing feature of this work, however, is that the activation barrier is allowed to vary with different positions of the H2 in the surface unit cell. This is a clever approach which captures much of the influence of the corrugated surface. Moreover, under these approximations, the dynamical equations become only three-dimensional and, in fact, are identical to those of an atom scattering from a rigid, corrugated surface but with a potential with a sink. The TDSE is solved by the FFT procedure. Hence, it is possible to treat diffraction, tunneling, and dissociative chemisorption by accurate quantum techniques, at least on this simple type of PES. 

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