Intended for advanced students of physics, chemistry, and related disciplines, this text treats the quantum theory of atoms and ions within the framework of self-consistent fields. It treats the structure and spectra of atoms and ions, their behavior in external fields, and their interactions, including collisions. Data needed for the analysis of collisions and other atomic processes are also included, making the book useful as a reference for researchers as well as students. In the main text, simple and convincing methods are used to explain the fundamental properties of atoms, molecules,...