Theoretical and Quantum Mechanics: Fundamentals provides an introduction to theoretical and quantum mechanics for chemists. The book includes carefully selected quantum mechanics topics of the most fundamental interest and use for chemists and classical mechanics topics that relate and illuminate these. A comprehensive treatment is given wherever possible. The book acquaints the chemists with the quantum structure of the basic object of chemistry - the atom - and the author bridges the gap between classical physics, general and inorganic chemistry, and quantum mechanics. The book provides the basics of theoretical and quantum mechanics in one place and emphasizes the continuity between them. Key topics include: - applications of quantum methods to simple systems, e.g. one-dimensional potential, harmonic oscillator, hydrogen atom, hydrogen-like atoms - introduction of representation theory and elements of matrix mechanics - development of the perturbation theory - physical explanation of the interaction of an electron with magnetic field - generalization to many-particles systems. Each chapter includes a detailed outline, a summary, self-assessment questions for which answers are in the text, a varied set of problems. In addition, the book contains many summary tables to ensure clarity of the subject.