Perturbation theory is a powerful tool for solving a wide variety of problems in applied mathematics, a tool particularly useful in quantum mechanics and chemistry. Although most books on these subjects include a section offering an overview of perturbation theory, few, if any, take a practical approach that addresses its actual implementation <

Perturbation Theory in Quantum Mechanics. Perturbation Theory in The Coordinate Representation. Perturbation Theories without Wavefunction. Simple Atomic and Molecular Systems. Bounded Domains. Convergence of the Perturbation Series. Polynomial Approximations. Scattering States. Classical Mechanics. Maple Programs. Appendices.