Generalized reaction-path Hamiltonian dynamics

The reaction-path Hamiltonian is reformulated in a form that is independent of the specific choice of guiding path. A necessary and sufficient condition for a given curve to satisfy reaction-path Hamiltonian requirements is derived, showing that any curve with no explicit dependence on the independent parameter does give rise to a formally acceptable reaction-path Hamiltonian. Numerical calculations have also been performed, comparing some reaction-path choices with the exact classical dynamics, evidencing the physically ground basis of most reaction path approaches.