He-HF碰撞体系相互作用势模型的理论研究

Theoretical Study of the Interaction Potential Model for He-HF System

根据在CCSD(T)/aug-cc-pVQZ理论水平下计算的He-HF相互作用能的数据,作者用Murrell-Sorbie势函数形式构造了He原子与HF分子相互作用各向异性的势模型,并与其它势模型进行了比较;然后采用公认的精确度较高的CC近似方法,计算了He-HF碰撞体系的微分散射截面,计算结果与实验结果符合较好.研究表明,作者所构造的势模型不但表达形式简洁,而且能较好地描写He-HF系统相互作用的各向异性特征;利用碰撞体系分子间势的量子化学从头计算结果,可解决势能参数难以确定的问题.对进一步研究原子与分子相互作用的机制有一定的参考价值.

The authors put forward firstly a new anisotropic interaction potential model based on the Murrell Sorbic potential function for He-HF system by applying the interaction energy data, which are 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 new potential model is compared with others models. Then the differential scattering cross sections for collisions between He atoms and HF molecules are calculated by using CC（Close-Coupling） method. The result of the calculation is in agreement with the existing experimental data. The research shows that the new potential model possesses not only advantage of the simpler function form but also is characteristic of expressing anisotropic interaction better for He-HF system, and that the potential parameters are more easier to fit based on the results of ab initio calculation for similar collision systerm. Thus, the results have some reference value for probing the interaction essential of atoms and molecules.