He-HCl体系散射截面随能量变化规律的研究

The Study of Law Concerning the Changes of the Scattering Cross Sections with Energies for He-HCl System

作者首先以拟合在CCSD(T)/aug-cc-pVQZ理论水平下计算的He-HCl相互作用能数据,获得了He-HCl体系相互作用的各向异性势,并与其它势模型进行了比较,验证了拟合势的可靠性;然后采用密耦近似方法,计算了He-HCl碰撞体系在不同碰撞能量下的微分散射截面、分波散射截面和总截面,得到了散射截面随能量变化的规律.研究表明:小角散射几率大于大角散射几率;碰撞能量越高,体系的散射几率越小,量子效应越不显著,尾部效应越弱,得到收敛的分波截面所需的分波数也越多.

The anisotropic interaction potential for He-HCI system has been obtained by fitting 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 reliability of the fitted potential is confirmed by comparing it with other potential models. Then the differential scattering cross sections, partial and total scattering cross sections under different energies for collisions between He atoms and HCl molecules are calculated by using CC（Close-Coupling） method. Furthermore, the varing rule of scattering cross sections with collision energies are summed up. The research shows that the scattering probability at large scattering angle is bigger than one at small scattering angle. And the higher collision energy is, the smaller scattering probability for collision system is, the less obvious quantum effect is, the weaker tail effect is, the more partial wave number of convergent PCS is.