Bonded – Preston J. MacDougall, PhD, Author, and Professor of Chemistry at Middle Tennessee State University – Atoms, Molecules & Quantum Theory

Preston J. MacDougall, Ph.D., author, and Professor of Chemistry at Middle Tennessee State University, delivers an overview of how atoms bond and the importance of quantum mechanical methods in modern scientific research.

As the former doctoral researcher at Los Alamos National Laboratory, MacDougall studied the computational modeling of materials. At Middle Tennessee State University, MacDougall is an integral part of the Molecular Biosciences and the Computational Sciences Ph.D. programs. MacDougall specializes in theoretical chemistry and the innovative development of quantum chemistry-based design tools specifically for pharmacology and molecular electronics applications.

MacDougall talks about quantum mechanical methods utilized to model the behavior of macroscopic systems such as plastics or enzymes, etc., systems that are too large to be treated by quantum mechanical theories that were developed for individual atoms. He discusses the modeling of bonds and when Newtonian mechanics can work versus when quantum mechanical methods become necessary.

The Ph.D. discusses bonding and electrons, and modeling methods in detail, and how quantum mechanics find 'lumps' in valence shells. A valence shell is the outer shell of an atom in its natural, uncombined state, and as such contains the electrons that are most likely to account for the nature of any possible reactions that involve the atom and also of any bonding interactions it may have with other atoms as well.

MacDougall explains that chemists are interested in atoms and ions as they exist in actual compounds. MacDougall talks about colliders, particle accelerators, and how they are used to fire electrons at targets, at nearly the speed of light. By studying how electrons scatter off after penetrating a nucleus, researchers can get a better idea of what the nuclear structure is like.

MacDougall continues his discussion of bonds, which are mutual attractions between two atoms. He explains how atoms are attracted, and how some may come close together as they are attracted, but they won't change or disturb the shape of either. But some other bonds, in which two atoms come close together, may cause them to deform and form a new bond or wedding. And by understanding the structure of electron clouds, scientific researchers can better understand why bonds are as they are, and how they function.