Mini-Symposium, Paper M2

Reaction Path Bifurcation: Valley-Ridge-Inflection Points do not
generally form isolated points on a PES

Wolfgang Quapp
Universität Leipzig

We have found that the old distinguished reaction coordinate [1] has bifurcation points at the valley-ridge-inflection points of the PES [2].

The new method of the reduced gradient [1] follows this old distinguished reaction coordinate in form of a defined equation. In an equivalent use of this equation and a so-called global Newton method we can calculate (symmetric) VRI points in a systematic manner. These points may be an indication for reaction path bifurcations.

In test calculations we have observed that VRI points are not isolated outsiders, but that they emerge in line-like or even
hypersurface-like accumulations, if the dimension of the PES is greater than 2.

[1] W. Quapp, M. Hirsch, O. Imig, D. Heidrich, J. Computat. Chem. 19 (1998) 1087.
[2] W. Quapp, M. Hirsch, D. Heidrich, Theor. Chem. Acc. 100 (1998) 285.