A theoretical study of the prereaction process of the H···HF van der Waals molecule

Abstract

Three-dimensional time-independent reactive scattering calculations have been carried out to simulate the dissociation process of the H···HF van der Waals (vdW) molecule by infrared excitation. The most recent abinitio potential energy surface of Stark and Werner has been employed to obtain the scattering wavefunctions, while the bound-state wavefunction for the H···HF vdW complex has been modeled with a simple harmonic oscillator. We have found the prereaction process, H···HF*→H₂+F, occurs in the tunneling region and also on the vdW resonance positions, where H···HF* corresponds to the quasi-bound vdW resonance state in which HF is vibrationally (or rotationally) excited, although the predissociation process, H···HF*→H₂+F, dominates in the energy range considered in the present calculations. This result indicates that both the prereaction and predissociation processes take place in the similar time scale at least on the Stark–Werner potential surface.