Using a functional form based on rotated Morse curves, cubic splines are used to fit the Shavitt-Stevens-Minn-Karplus (SSMK) potential surface for the collinear H+H2 reaction. The fit obtained by this method is shown by contour maps and difference maps to be excellent. The deviations which do occur are shown to result from the limitations of the method but also from an error in the SSMK function. Classical trajectories carried out on the spline-fitted surface show good agreement with the results obtained from the analytical SSMK surface, including a point-by-point matching of most of the individual trajectories. The reactivity bands and total reaction probability agree closely with the two methods. The spline-fitted potential function is more economical to use than the analytical function and is easily adjusted to give different surface features, which may be varied in an independent manner. Copyright

The Journal of Chemical Physics
Department of Chemistry

Gray, S.K. (Stephen K.), & Wright, J.S. (1976). Classical trajectories for the H+H2 reaction on a spline-generated potential energy surface. The Journal of Chemical Physics, 66(7), 2867–2873.