A Journey with Good Companions. Fifty years of Quantum Chemistry

• Published in: Advances in Quantum Chemistry Vol. 34; pp. 1 - 50
• Main Author: Craig, David
• Format: Book Chapter
• Language: English
• Published: United States Elsevier Science & Technology 1999
• Subjects: Animal husbandry; Atomic & molecular physics; Quantum & theoretical chemistry
• ISBN: 9780120348343; 0120348349
• ISSN: 0065-3276; 2162-8815
• DOI: 10.1016/S0065-3276(08)60530-4

This chapter presents the various developments that took place in the field of quantum chemistry in the last five decades. Quantum chemists in the mid-forties focused on how to improve the methods of describing the electronic structure of molecules, valence theory, properties of the low excited states of small molecules, particularly aromatic hydrocarbons, and the theory of reactions. Although quantum electrodynamics had not yet been developed in a form convenient for treating the interaction of radiation with slow moving electrons in molecules, there were semi-classical methods that were adequate in many cases. To those who began work in quantum chemistry in England after the Second World War, the scene was sparse. Sir John Lennard-Jones had returned to the Theoretical Chemistry Department at Cambridge, and there were small theoretical groups in Manchester, Liverpool, and other places. The activity in the US had continued more strongly in the war years, diminished but still lively. Computational Chemistry being the leading example, became a subject in its own right, going forward magisterially with advances in computer power, realizing calculations that fifty years ago were dismissed as wildly out of reach, such as plotting decomposition pathways, and predicting structures of stable and metastable species.