This course uses quantum mechanics to describe atomic and molecular structure and bonding. The theory of these systems is treated first and their spectroscopy afterwards. The following topics are covered: motivation for quantum mechanics, Schrödinger’s equations, quantum postulates and formalisms, solutions of the time-independent Schrödinger equation for model systems (particle in a box, harmonic oscillator, rigid rotor, hydrogen-like atoms), angular momentum operator, electron spin, many electron atoms, theories of chemical bonding (valence bond theory and molecular orbital theory), quantum mechanics of the internal motion of molecules, spectroscopy of atomic and molecular systems.