A mixed quantum-classical semirigid vibrating rotor target approach to methane dissociation on Ni surface

A mixed quantum-classical semirigid vibrating rotor target (QC-SVRT) approach is presented to study dissociative chemisorption of polyatomic molecules on solid surface. In the four-dimensional flat surface study, the translational motion of the polyatom is treated classically while the rovibrational motion is treated quantum mechanically using the semirigid vibrating rotor target (SVRT) model. The QC-SVRT approach is computationally efficient and is ideally suited to treating polyatomic molecules due to their heavy translational masses. This QC-SVRT method is applied to calculating dissociation probability of methane on a Ni(111) surface which was studied previously by the full quantum-mechanical semirigid vibrating rotor target (QM-SVRT) method. Numerical results show that the current mixed method gives dissociation probabilities that are in reasonable agreement with the quantum results and the reaction threshold is correctly produced. The agreement of the QC result with the quantum one is good for the initial ground state, but less satisfactory for the excited state. (C) 2003 American Institute of Physics.