In the present seminar the modern theory of electric conductivity as emerged by the fundamental works of Kohn will be exposed and analyzed, as well as extensions and translations to a language closer to the Quantum Chemistry formalism.
In particular the role of the localization tensor, and its importance in defining a suitable metal-insulator transition (MIT) will be presented.
Applications to simple model systems (linear lithium chains) will be presented, showing the role of the inclusion of electronic correlation (treated at Full Configuration Interaction level).
Particular emphasis will be devoted in analyzing the difference between the localization tensor (modern theory of conductivity) and other more classical ways of defining MIT (band-gap closure, polarizability). The influence of disorder on MIT (Anderson transition) will also be presented studied for the first time on the framework of localization tensor.
Finally an example devoted to the study of the electric properties and conductivity of graphene nano-ribbons and nano-islands will be presented.