aUniversité de Lyon, laboratoire de chimie, École normale supérieure de Lyon, CNRS, 46, allée d'Italie, F-69364 Lyon, France
Abstract:
The efficiency of ab initio wavefunction based methods is demonstrated using various systems characterized by the presence of open shells. It is recalled that the low-energy spectroscopy of molecular architectures as well as extended materials is accessible and can be rationalized by including in a hierarchical way the valence (i.e. non-dynamical) and dynamical correlation effects. Such methodology not only allows one to investigate vertical transition energies but also gives access to a possible reading of the wavefunction in the ground and excited states.