Lifetimes and dissociation pathways of the quasi-bound states of the Na center dot center dot center dot FH van der Waals molecule

The highly reliable potential energy function for the ground electronic sta te of the NaFH system based on the ab initio multireference configuration i nteraction calculations [M.S. Topaler, D.G. Truhlar, X.Y. Chang, P. Piecuch , J.C. Polanyi, J. Chem. Phys. 108 (1998) 5349; V. Spirko, P. Piecuch, O. B ludsky, J. Chem. Phys. 112(2000) 189] is used to calculate the energies, wi dths, and dissociation pathways of the quasi-bound states of the Na FH van der Waals molecule. Although emphasis is placed on the quasi-bound states r esulting from vibrational excitation of the HF fragment in the complex, the bound states and the quasi-bound states, in which the HF fragment is not e xcited, are investigated as well. The study focuses on assessing the reliab ility of the earlier stabilization calculations [V. Spirko, P. Piecuch, O. Bludsky, J. Chem. Phys. 112 (2000) 189] by performing independent close-cou pling calculations for the outgoing scattering waves of the NaFH system. Th e probabilities of decay of the Na . . . FH ro-vibrational resonances into various Na + HF(v,j) channels provide new insights into the dynamics of dis sociation of the Na . . . FH complex. (C) 2000 Elsevier Science B.V. All ri ghts reserved.