**[Cr:4, Lc:3, Tt:1, Lb:0]**

- Time independent and time dependent perturbation theory. Transitions under the action of a perturbation acting for a finite time, Transitions under the action of a periodic perturbation.
- Review of Hydrogen atom, Fine structure, Hyperfine structure as an application of perturbation theory to real systems. Zeeman effect, Stark effect.
- The semi-classical approach, WKB approaximation. Penetration through a potential barrier.
- The variational principle, applications.
- Scattering theory: Scattering cross-section, partial waves, Yukawa and Coulomb potentials, scattering by square well potential, reaction rates, mean free path, retarded potentials, Born approximation.
- Relativistic quantum mechanics: Klein-Gordon equation, negative probabilities. Dirac equation, relativistic free particle solutions, negative energy solutions, anti-particles. Zitterbewegung.

- B. H. Bransden and C. J. Joachain, Physics of Atoms and Molecules, 02nd edition, Pearson Education (2008).
- P. Atkins and J. De Paula, Physical Chemistry, 08th edition, Oxford University Press (2009).
- J. J. Sakurai, Quantum Mechanics, Addison Wesley Low Priced Edition (2008).
- L. I. Schiff, Quantum Mechanics, 03rd edition, McGraw-Hill (1968).
- W. Demtroder, Atoms, Molecules and Photons, Springer-Verlag Berlin (2006).
- J. B. Rajam, Atomic Physics, S. Chand & Company Ltd. (2007).