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

- Two spectroscopic models: The harmonic oscillator and the rigid rotor, description of a diatomic molecule, energy levels of a quantum-mechanical oscillator, Hermite polynomials. The rigid rotor, energy level of a rigid rotor, spherical harmonics, description of hydrogen atom, SchrÃ¶dinger equation for the helium atom.
- Approximation methods: Time-independent perturbation theory, non-degenerate perturbation theory, degenerate perturbation theory, applications, variational method and its applications, description of helium atom using variational and perturbation method.
- Multi-electron atoms: Born-Oppenheimer approximation, symmetric and anti-symmetric wave functions, spin orbitals and spatial orbitals, Hartree products, Slater determinants, the Hartree-Fock approximation, configuration interaction, the Coulomb and exchange operators, spin adapted configurations, term symbol, description of electron configuration, description of atomic spectra using term symbols, Russell-Saunders coupling.
- Description of molecules: Valence bond treatment and stability of bonds, molecular orbital theory and its applications in simple systems, molecular orbital theory of polyatomic molecules, the concept of delocalization, conjugated systems, butadiene.

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- G. C. Schatz, M. A. Ratner, Quantum Mechanics in Chemistry, 1st Ed, Dover Publications, New York, (2002).