DYNAMIC INVESTIGATIONS ON "ATOM-DIATOMIC MOLECULE COLLISIONS"

Abstract

This work comprises five chapters. Chapter I includes an introduction to the present work and the structure of the thesis.

Chapter 2 includes complete knowledge about the concept of the Potential Energy Surfaces (PESs) which is needed in either collision or transition state theories of chemical kinetics, this knowledge of the (PES) functions come from approximate solutions to the electronic Schrodinger equation.. We shall show that the concept of potential energy curves and surfaces arising from the adiabatic-approximation, is the basis of the quantum mechanical treatment of the dynamics of elastic, inelastic and reactive collisions. On the basis of the adiabatic-approximation, we can calculate in principle, the (PES) of any system of interacting atoms and molecules.

Chapter 3 includes details about the structure of the (PESs) in both functional and graphical representations. We have employed two types of (PESs) representations, the first type is the functional representation which includes two widely differing approaches to the calculation of (PESs), the tirst approach is a semi-empirical method which contains some adjustabk parameters and fits the known experimental results, the second approach is the ab-initio calculations in which the Schrodinget• equation is solved numerically by methods that have been well established for stable molecular systems and are finding increasing application in reaction kinetics, since these surfaces are not empirically adjusted, they provide independent information of the shape of the surface and on the mechanism of the reaction. The second type is the graphical representation, in which the (PESs) at•e represented by 3D-computer movies, contour map. We shall show in details the structure of the (PESs) that we have employed in our calculations in both functional and graphical representations. We have modi tied