He-HF体系势能模型对散射截面影响的理论研究

用BFW势函数拟合在CCSD(T)/aug-cc-pVQZ理论水平下计算的He-HF相互作用能，获得了He原子与HF分子相互作用的各向异性势，并与其他势模型进行比较，验证了拟合势的可靠性；然后采用量子密耦(Close-Coupling)方法分别计算了He-HF碰撞体系在五种不同势能模型下的微分散射截面、分波散射截面和总截面，并对计算结果进行了详细的比较和分析.研究表明：势能球平均零点能位置、势阱深度、排斥势的强度以及势能在势阱附近的方向性都对散射截面有较大影响. 关键词： 势能模型 密耦方法 散射截面

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

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.