Nonrelativistic quantum mechanics, study

The study of matter at a molecular and sub-molecular level requires a quantum mechanical framework. In this chapter, we provide an overview of the essential concepts and notation of quantum theory needed to understand the development of relativistic many-electron quantum mechanics. This introductory overview starts from basic axioms with a focus on the nonrelativistic theory. Gauge and Lorentz invariance properties as introduced in the classical theory are then discussed for the basic quantum mechanical equations in the following two chapters. 

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