COMPENSATING HAMILTONIAN METHOD FOR CHEMICAL-REACTION DYNAMICS - XE DESORPTION FROM PD(100)

We report on a method that allows us to study with molecular dynamics a chemical reaction with an activation barrier that is much higher than the thermal energy. The method leads to a new Hamiltonian with which it is possible to compute reaction rate constants, and reactive trajectories even at low temperature. The method is applied to Xe desorption from Pd (100). The desorption rate constants are compared with transition state rate constants. The mechanism of the desorption is studied, and a model is given that explains the molecular dynamics results. Conversion of lateral into normal kinetic energy during the desorption process is shown to be important.