Selective adsorption of H 2 + Cu(001) surface : II. Quantum mechanical calculation of quasibound compound states

Abstract

The selectively adsorbed compound states for H 2 + Cu rigid surface scattering, which are the quasibound states embedded in the continuum, are computed employing quantum mechanical method. With a semi-empirical molecule-flat surface interaction potential, we diagonalize the total Hamiltonian of the system including the rotational and vibrational states of the molecular projectile. Our emphases here are to study the vib-rotational and vibrational components that are proportional to the scattering amplitude of the Feshbach type internal excitation associated with selectively adsorbed resonance states, to study the relative importance between the rotational and vibrational mediations for selective adsorption, and to make comparison with quasiclassical trajectory results obtained in the preceeding paper. For incident energy below ∼ 0.3 eV, rotation mediations are found to be dominant in the resonance scattering, whereas the resonance states that arise from the vibrational mediation often appear above that energy. Good agreement between the quantal and the classical trajectory results is obtained regarding the energies of the selectively adsorbed quasibound states and other related physical quantities in the energy region above the potential barrier. Below this barrier, the quantum mechanical tunneling effect is important.