He-H_2(D_2、T_2、HD、HT、DT)碰撞体系积分截面的理论计算

Theoretical Calculation of the Integral Cross Sections for He—H_2(D_2,T_2,HD,HT,DT)System

采用量子化学从头计算方法,在CCSD(T)/AUG-CC-PV5Z+bf(3s3p2d1f)水平下,计算了He-H2(D2、T2、)碰撞体系在不同入射角时的相互作用能数据,运用质心变换-拟合方法、采用Tang-Toennies势模型和非线性最小二乘法拟合、构造了He-H2(D2、T2、HD、HT、DT)碰撞体系各向异性势在不同方向上的径向系数和振转相互作用势。通过密耦近似方法计算了入射原子能量分别为60、90和120meV时,各碰撞体系的积分截面。根据计算结果,进一步分析讨论了积分截面随体系约化质量和入射能量变化的规律及各类积分截面的特点。

The interaction potential surfaces of He-H2 （D2, T2）have been calculated by employing ab initio method at the CCSD（T） /AUG-CC-PV5Z＋bf （3s3p2d1f） calculational level when the incident angles was different. The vib-rotational interaction potentials and the radial coefficients of anisotropic intermolecular potential in different directions of He-Hz （D2 ,T2, HD ,HT.DT） system were fitted using the method of center of mass transformation-fitting, the Tang-Toennies potential function and nonlinear least square method. The integral cross sections at the energies of 60,90 and 120 meV have been calculated by using the quantum Close-Coupling method. On the basis of the above result, the change rules and the characteristic of the integral cross sections with change of the reduced mass and the incident energy of systems have been discussed. Tang-Toennies potential function, differential coefficient cross sections, scatterimg angle