ABSTRACT
The preceding six chapters have addressed physical properties of solids viewed as continuous media. However, many important properties of technological materials dependupondetails of the atomic structure that cannot be adequately represented by continuum models, or even by classical discrete atoms. An obvious example is optical properties due to chemical impurities. More generally, however, it is interesting to ask to what extent arbitrary properties of a solidmaterial can be related directly, and rigorously, to the nuclei and electrons of which the material is ultimately composed. The nuclei specify the chemical composition of the solid and, thereby, the crystal and defect structure under given thermodynamic conditions; whence also both equilibrium and dynamical properties and processes. In this chapter we shall illustrate how the thermodynamic equation of state of a solid is related to the electrically neutral collection of nuclei and electrons of which it is made up. We shall establish a formal framework so that the reader can see how, by improving the initial model, and by adopting one or another set of systematic approximations in the mathematical treatment, one can simulate an extremely wide range of phenomena. The approach will be based on elementary concepts of quantum mechanics and statistical thermodynamics. In later chapters it will become evident that, given presently available computing power, implementation of large parts of this agenda for specific materials and properties is a practical undertaking. Much of this chapter closely follows Maradudin (1974).
