Dynamic Analysis of Wave Packet Behavior Over Time in Adiabatic and Nonadiabatic Reactive Scattering Scenarios

Understanding the chemical transformation of substances and predicting its outcomes lies in the heart of chemistry. As is well known, a chemical change takes place when the reacting species, or say the reagents change their chemical identity by breaking the old chemical bonds to produce the products forming new bonds. These chemical transformations take place in between the atoms or molecules of the reagents. Hence, a molecular level understanding of these processes is necessary in order to explain the underlying mechanism. This field of study falls under a broad umbrella of molecular reaction dynamics. The central theme of molecular reaction dynamics is to gain an in-depth understanding of the chemical processes at the microscopic level. Basically, it concerns with the answers to the fundamental questions, "how exactly does a chemical reaction occur? how to predict and control its outcomes?". Analysis of reaction dynamics in many senses is different from the bulk kinetics study of the chemical reactions. Most importantly, in bulk kinetics studies the reaction rate is measured under the thermal equilibrium condition. In such cases the measured rate constant involves many averages over all the accessible states of reagent and product. As a limitation such studies are not capable to provide the detailed required information about the re- action at a molecular level which is lost due to averaging. In contrast, the study of molecular reaction dynamics offers a microscopic level understanding of the reactions without averaging any information, and seek to explicate what actually happens to the atoms or molecules during the reaction events. In addition, the information obtained from reaction dynamical studies can provide any particulars of the reaction in regard to the bulk kinetics with appropriately averaging whenever required.

Most of the chemical phenomena occurring in the universe involves a series of or a chain of basic single reaction steps. These individual steps are known as elementary chemical reactions. The elementary reactions are generally part of big chemical reaction networks which spans from simple molecules to complex molecular systems. They play a central role in elucidating the mechanism of the whole reaction network.