Fernando Bernardi

Applications of computational chemistry to the modelling of organic reactivity in ground and excited states

A review of methods for modelling chemical reactivity in ground and excited states is presented. The central problem is related to the correct representation of the changes in the spin‐coupling at a transition state or in an excited state. Both MC‐SCF and a hybrid method MM‐VB are discussed. The application of these techniques to photochemistry is one of the newest challenges to quantum chemistry. The applicability of modelling methods to this type of application is discussed.

Quantitative Orbital Analysis of Structural Problems at the Ab-Initio Scf-Mo Level

Qualitative Perturbational Molecular Orbital (PMO) procedures have prooved to be a very useful instrument for analysing the energy effects associated with the orbital interactions occurring between the component fragments and for understanding a variety of chemical-problems (1–7). The methodology employed in these studies is founded upon One Electron Molecular Orbital (OEMO) theory and usually involves the following steps: (i) sequential dissection of the molecule under consideration into component fragments; (ii) construction of the group MO’s of each fragment; (iii) evaluation of the interaction energy which obtains in the course of the union of the component fragments to yield the composite system in a specified geometry.