This story is prepared because when I saw the words CC for the very first time, it meant very little to me. I felt I should record how I sought to understand CC and what CC means to me now I am enrolled on 28/4/00. Maybe my experience could be useful to prospective students?
I was then looking at a Graduate Diploma in Science NTU. The Course Coordinator advised it was important I identify some existing interest within the School of Biological, Environmental & Chemical Sciences if I were to expect enrolment. I felt all the units and research interests were 'ordinary' except for CC. It caught my eye simply because I had never previously seen the term. But the Handbook did not inform what was CC? Associate Professor Brian Salter-Duke mentions his research was linked to the Nobel Prize 1998 of John Pople -
"Model chemistries such as the Gaussian-2 and Gaussian-3 methods developed by 1998 Chemistry Nobel Laureate Professor John Pople and colleagues have revolutionised the ability computational chemists to predict reaction enthalpies to a high degree of accuracy. The extension of these methods to molecules containing the 3rd and 4th row atoms has shown real promise but much remains to be done. This project will build on work already completed at NTU."
The Royal Swedish Academy of Science press release for the Pople Nobel Prize 1998 was the material I needed.
Citation: "to Walter Kohn for his development of the density-functional theory and to John Pople for his development of computational methods in quantum chemistry."
The history of the development of chemistry is traced. Let our point of departure at this time be 30 years ago when quantum chemistry was not seen as useful to chemistry. This has changed. There is no question the advance is one the greatest advances in chemistry over the two decades. There were a series of developments by Pople but here we only note the emergence of model theoretical chemistry. This focussed on the structure of a molecule, the bond distances and bond angles. Pople compiled his work into a computer program Gaussian. Later work incorporated perturbation theory to calculate perturbation energy. A second order approach for energy derivatives were considered important.
I was particularly impressed by three diagrams:-
Note: If these download slowly it is because they are fetched from the Nobel Prize web site in Sweden.
Fig. 1. Electron density in the amino acid cystein calculated using a quantum-chemistry computer program. The picture shows the surface where the electron density is 0.002 electrons/Å3 (meaning that nearly all electrons are inside the surface). The grey scale shows the electrostatic potential at this surface, darker portions representing negative potential.
Fig 2. High up in the atmosphere, CF2Cl2 molecules (freon, left in picture) are destroyed by ultraviolet light. Free chlorine atoms are formed, which react with O3 molecules (ozone, right in picture) and destroy them. The process can be studied using quantum-chemical calculations.
The third diagram is of a potential energy surface for a simple reaction in the additional background information on the Nobel Prize in Chemistry 1998. This is in a Acrobat pdf file so we can not access just the diagram.
NOTE! If the above link doesn't work, the reason could be that you don't have the program Acrobat Reader - see bottom of page.
Some dynamic models also impressed me. We have put these on a separate page as you will need the Chime pluggin to view them. If you do not have Chime give it a miss, but you may be tempted to get Chime and install it in order to view these molecules.
Areas where quantum chemistry theory is used for chemical and molecular physics are:-
Written: 30 April 2000
