The book shows how to apply these numerical methods to obtain many different characteristics of atoms, molecules, and the various processes within which they interact. In an entirely self-sufficient approach, it teaches the reader how to use the codes provided to build atomic and molecular systems from the ground up and obtain the resulting one-electron wave functions. The computational programs presented and made available in this book allow calculations in the one-electron Hartree–Fock approximation and take into account many-electron correlations within the framework of the random-phase approximation with exchange or many-body perturbation theory.