Quasiclassical Trajectory Calculation Of The Chemical Reaction Ba+HBr, Ca+CH₃Br, Sr+CH₃Br

At present,the reaction between alkaline earth metal atoms and halide obtained comprehensive attention in the international area.In recent decades,with the rapid development of experimental detection technology and computer technology,more and more people focus on the study of molecular reaction dynamics and the discussion of the reaction mechanism.In the aspect of experiments,using the technologies of infrared Chemiluminescence(CL),Cross Molecular Beam and Laser-induced Fluorescence (LIF),the state--state chemical reaction can be studied and the detailed results of molecular reaction dynamics can be detected.This work provides an important experimental basis in order to reveal the reaction process and study the reaction mechanism.At the same time,theoretical scientists have done a lot of work,the methods which are used to study the chemical reactions now are mainly quasi-classical trajectory method,semi-classical method and the method of quantum theory(including the time and time-dependent dynamics theory) and so on,the most widely used method is the quasi-classical trajectory method.Quasi-classical trajectory method based on the molecular collision theory,by solving the classical Hamiltonian equations of motion to simulate the movement process of the reactants which are on the potential energy surface,so as to arrive at the purpose of repeat the results of reaction which are achieved in the experiment and analysis the reaction mechanism in theory.Because that the quasi-classical trajectory method is more intuitive,which requires less computer resources,more simple operation and more exact calculation results and so on,it has already become an important method to study the molecular reaction dynamics and has been used to study a large number of chemical reaction system in the theoretical side.In this thesis,the quasi-classical trajectory method has been used to study the three chemical reaction systems that are Ba+HBr,Ca+CH₃Br and Sr+CH₃Br system.Through the calculation of the trajectories,we can obtain the results of molecular reaction dynamics,such as the vibrational distribution,rotational distribution,the reaction cross section and the product rotational alignment of the tree systems.And compare the theoretical calculation results with the experimental results in order to give a reasonable explanation and theoretical prediction about the experimental results.Through our calculation results,we found that the quasi-classical trajectory method can simulate the experimental results very well and the theoretical results which are obtained through the calculation are less disagreement with the experimental results. The mechanism of the reaction can also be given a reasonable theoretical explanation.