Molecular Hamiltonian operators; classical Hamiltonian; Hamiltonian in the laboratory and internal coordinate systems. Born Oppenheimer approximation. Potential energy surfaces. Jahn Teller and Renner Teller effects. Diabatic corrections. (6h) Hartree-Fock and Hartree-Fock-Roothaan methods. (2h) Electronic correlations (4h). Configuration interaction and coupled cluster methods (4h). MC-SCF and UHF methods (4h). Density matrices (2h). Moller-Plesset perturbation theory (Mod. A, 4h). Valence Bond and Spin-Coupled methods. Covalent structures and the Perfect-Pairing approximation; hybrid orbitals. Ionic configurations and polarized orbitals (3h). Theory of chemical reactivity (3h).