Developments in computer architecture and the birth and growth of computational chemistry

It goes almost without saying that the impressive development of computational chemistry in the past 50-60 years is a direct consequence of the even more impressive developments in computer hardware and software in that same period. However, this development also required the vision and skills of pioneering scientists that saw the new possibilities early, such as Roothaan and students at the University of Chicago, Slater’s group at MIT, and the Boys group at Cambridge, United Kingdom. Yet, we might recall in this context that it was a chemical physics problem, the calculation of the dielectric constant of Helium, that inspired John Atanasoff, working on his PhD thesis in Madison, Wisconsin in 1930, to think about designing an electronic calculating machine. About 10 years later, at Ames, Iowa, with the help of his student Clifford Berry, he succeeded in building the first electronic computer-the ABC, the Atanasoff-Berry computer. Because of war circumstances, this invention was never patented and only in October 1973 it was legally settled that the ABC and not the ENIAC was the first electronic computer ever built. A fairly complete account of this interesting episode in computer history can be found on the site www.columbia.edu/∼td2177/JVAtanasoff/JVAtanasoff.html.