Tight Binding Methods for Metallic Systems

The atomistic description of metal systems, which is the central topic of this book, is only possible through application of quantum theory. For the great majority of the metallic systems of interest, achieving a quantum description of some phenomena requires a delicate balance between two competing requirements: the degree of realism of the physical model and the level of approximation in the quantum treatment. A third requirement is fundamental: we need a transparent interpretation of the theoretical model, because otherwise we obtain numbers without any physical significance. In the end, some compromise between these two (or three).