He原子与O_2分子相互作用势及碰撞微分截面的研究

A theoretical study on interaction potential energy surface of He-O_2

本文用量子力学从头算方法深入研究了He原子与O2分子的相互作用势,选定CCSD(T)/6-311++G(3df,2pd)方法和基组,同时采用了Boys和Bernardi提出的Full Couterpoise方法消除了计算中的基组重叠误差(BSSE),得出了该体系的各向异性相互作用势的单点能数据,通过拟合得到了较为准确的He-O2体系相互作用势的解析表达式.采用精确度较高的密耦(Close-Coupling)近似方法,计算了He-O2碰撞体系的碰撞激发微分截面,计算得到的微分截面数据与实验值符合较好,并得出了不同碰撞能量时He原子与O2分子的碰撞的微分截面的规律.

In this paper,the ab initio quantum mechanics method is used for a further investigation of the interactional potential energy functions of He atom and O2.By means of different methods and basis sets,the energy data in the space have been calculated.Finally the accurate He-O2 interactional potential energy functions are obtained by using QCISD（T）/6-311＋＋G（3df,2pd） with Boy and Bernardi’s Full Couterpoise to eliminate the basis set superposition error（BSSE）.The calculated differential cross sections of He-O2 collision are in good agreement with the experiment data.The rule of differential cross sections of He-O2 collision at different collision energies has been derived.