An introduction to the quantum Theory for chemists : An expérimental approach

This little book is a brief introduction to the quantum theory for chemists. In it I keep as close to experiment as possible, and to ideas that are familiar to chemists. This approach takes me away from one based on mathematics. There is some mathematics, but I have kept this as simple as possible. The quantum theory is used in chemistry in two main ways. One is to make accurate calculations of the energies of chemical processes. These calculations are very complicated but are made possible by modern computers. Algorithms are now available for chemists to use. An example of such a calculation is that carried out on the sodium‒helium system at various pressures leading to the prediction that Na2He would be stable above 1.6 × 106 bar, a prediction verified by experiment. Chemists also use the results of approximate calculations to understand chemical phenomena and make tentative predictions. It is possible, for example, to explain the Periodic Table on the quantum theory, as we shall see in a later section. In this book, we shall keep the two uses of the quantum theory in chemistry in mind. We shall gradually build up the principles behind accurate calculations while also discussing some of the results from more approximate treatments.