The Potential Energy Surface Construction Of LiHf System And Dynamics Study Of ArH₂⁺ System

As a typical and very simple ion-molecule reaction,a lot of works have been performed on LiHF system for years.Being a reaction between rare gas and the ion of the hydrogen gas,ArH₂⁺not only plays important roles in high energy physics,astrophysics and plasma physics,but also takes significant parts in atmospheric physics and environmental protection.Li HF reaction and ArH₂⁺ reaction are both simple prototypes,the extensive studies on them can help us to study the other complex ion-molecule reactions.Moreover,the two reactions are of significance in understanding the collision processes in interstellar media,the plasma,and high-energy physic studies.This dissertation is composed of two parts.The first part describes the constructions of the ground potential energy surfaces?PESs?for Li+HF system.The other part is about the dynamics studies of the Ar+H₂⁺ system.In the third chapter,this study mainly focuses on the potential energy surface of the ground state and presents a new fit to the most recent ab initio energy points,a high-level ab initio electric calculations for the PES has been carried out in the ground state of Li+HF.We choose the UCCSD?T?method,which made it possible to construct a rather accurate analytic representation of the lowest-energy Li+HF PES.The details of the PES are presented by means of contour maps for a variety of angles and distances.The newly presented Li+HF fit is compared to several previous PESs of the ground state that have appeared in the literature.As a result,the new PES shows a rather good agreement with the available experimental data,indicating our work is significant for further Li+HF system study.It is important to study both scalar properties and vector properties to fully understand the dynamics of an elementary reaction fully.And the reaction dynamics about Ar+H₂⁺ is studied using QCT method in the fourth chapter,based on the new PES used in the multireference configuration interaction method with Davidson correction?MRDCI?consisted of the aug-cc-pVTZ basis set.The research the influence of isotopic substitution and rotation excitation on Ar+H₂⁺ system is also explored.The isotopic is revealed by a very slow decrease for largemass factor.In the end,we give a conclusion of this dissertation.