Postulates of quantum mechanics, operators, angular momentum. Solution of hydrogen atom problem, theory of atomic spectra, self consistent field theory. Compulational aspects. Perturbation and variation methods. Probability distribution laws. Statistical basis of entropy. Molecular partition functions: evaluation and applications. The canonical ensembles. Some applications of statistical thermodynamics. Maxwell-Boltzmann of velocities, heat capacities, equipartition of energy, equilibrium state.