Schatz and Elgersma

Schatz and Elgersma [161] have published an analytic surface for the reaction of Eq. (5.4). This surface has a relatively simple reaction path, somewhat like that of Figs. 4 and 5. To test the interpolation procedure thoroughly at reasonable cost, we pretend that this analytic surface supplies us with the ab initio data, and we require that our converged interpolated surface will give us the same classical trajectory result for the probability of reaction as the analytic surface [204]. 

Figure 16. Reaction probability versus the number of data points defining the PES via Eq. (7.5) and the iteration procedure described in the text (filled circles), and via a data set composed of 729 randomly generated, energetically allowed configurations (cross). In all cases the value p = 9 was used in Eq. (7.4). The iteration procedure started with 30 points along the MEP. The reaction probability obtained from the surface of Schatz and Elgersma is shown as a dashed line and error bars represent standard deviations.

Figure 18. Angular momentum distributions of the (a) H2O reaction product and the (b) OH and (c) inelastic collision products as the number of data points defining the interpolated surface is iteratively increased from 30 (open circles) to 400 (crosses) as in Fig. 16. The angular momentum distributions obtained from the surface of Schatz and Elgersma are also shown (filled circles) where the error bars represent standard deviations. The HjO distributions were obtained using bin sizes of 4h, whereas the OH and Hj distributions used bin sizes of 2ft.

Figure 19. Reaction probability versus initial vibrational excitation of the molecule for the surface of Schatz and Elgersma (filled circles) and for the interpolated PES (open circles) generated from the first 400 data points of Fig. 16. Error bars represent standard deviations. The interpolated PES was generated for an H, initial vibrational excitation of about 0.085 hartree.

A more detailed analysis of energy consumption and disposal in reaction (R2) is given in the previous chapter by Schatz and Elgersma in this book. 

G. C. Schatz and H. Elgersma, A quasi-classical trajectory study of product vibrational distributions in the OH 4- H2 H2O + H reaction, Chem. Phys. Lett. 73 21 (1980). 

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