Theoretical study of the effect of potential models on scattering cross sections for He-HF system

Abstract

An anisotropic intermolecular potential of the He-HF complex has been obtained by utilizing the BFW analytic function to fit the intermolecular energy data, which have been calculated at the theoretical level of the single and double excitation coupled-cluster method with noniteractive perturbation treatment of triple excitation CCSD (T). And the reliability of the potential has been verified by comparing it with other potential models. The differential, partial and total scattering cross sections for collisions between He atoms and HF molecules have been calculated respectively by using the quantum close-coupling method at five different potential models, and the calculated results have been compared and analysed in detail. The research shows that the scattering cross sections are sensitive to the position where potential is zero, the well depth, the strength of the repulsive wall of the spherically averaged and to the anisotropy of the region of the well depth. We hope that the results can provide profitable reference for determining exactly the interaction potential of the atomic-molecular collision systems from the scattering cross sections.

Influence of Isotope Substitution Helium Atom on Partial Cross Sections in He-HF Collisions

“…Our fitted potential not only possesses the characteristic of the accurate SAPT potential, but offers a simpler expression with fewer parameters for the interaction in 4 He-HF. [13] 3…”

“…However, the SAPT potential energy surface is of a complicated analytic expression with at least 136 parameters, which result in the difficulty to study adequately. Recently, we have obtained an anisotropic potential [13] for the He-HF interaction by employing non-linear least square method to fit the intermolecular interaction energies computed using the augmented correlation-consistent polarized quadruple zeta basis set aug-cc-pVQZ at the theoretical level of the single and double excitation coupled-cluster method with noniterative perturbation treatment of triple excitation CCSD(T), and the influence of different potential energy models on scattering cross sections has been discussed. However, So far as we know, little has been reported on the influence of isotope substitution on atom-molecule collisions and few data are available.…”