Theoretical and computational chemistry in Italy

Abstract

This special issue collects 15 papers by Theoretical and ComputationalChemists based in Italy, which highlight the remarkable contributions provided by Italian scientists younger than about 50 years.I have tried to include the most significant research groups, with the exception of those who have published IJQC reviews in the last two years (in particular the groups leaded by Benedetta Mennucci in Pisa, [1] Ettore Fois in Como, [2] Marco Garavelli in Bologna [3] and the CRYSTAL group based in Torino and coordinated by Roberto Dovesi and Piero Ugliengo [4] ). Some contributions explore new and fascinatic topics, whereas some others follow more traditional paths pioneered by leading Italian scientists of the previous generations (e.g. development of new effective ab initio methods for large molecules and periodic systems, continuum solvent models, and ab initio molecular dynamics, pioneered by Enrico Clementi, Cesare Pisani, Jacopo Tomasi, and Michele Parrinello, respectively).Density functional theory (DFT) is undoubtedly the most popular electronic structure method for calculating energies and geometries for molecules and solids due to its reasonable cost and accuracy, but with well-known deficiencies. In this connection, the contribution by Fabio Della Sala reports new developments in the kinetic energy part of functionals, [5] whereas the contribution by Mauro Stener introduces new developments of the time-dependent extension of DFT (TD-DFT), [6] allowing the study of very large systems of relevance, for instance, for plasmonics. As mentioned above, the extension of methods for treating isolated molecules to condensed phases is one of the most well known contributions of Italian theoretical chemistry. New developments in this connection are described by Chiara Cappelli in her contribution.[7]The development of effective methods allowing the treatment of dynamical effects is another key development of recent years. In this connection Emilia Sicilia discusses the kinetics of complex reactions, [8] Dimitrios Skouteris reviews recent developments of time-independent and time-dependent approaches for isolated systems, [9] and Rocco Martinazzo analyzes analogous tools for processes at solid surfaces.[10]Accurate geometric structures are mandatory for the computation of reliable physical-chemical properties and also provide the most important contributions (via inertia moments) to microwave spectra. In her contribution, Cristina Puzzarini analyzes the status and perspectives of accurate structure computations for molecules of increasing dimensions.[11] Computational spectroscopy is becoming more and more important due to the difficulty of interpreting experimental results without the help of quantum mechanical simulations and to the continuous increase of accuracy and feasibility of this kind of computations also for non-specialists.The specific cases of NMR relaxometry in flexible molecules, solid state NMR and vibrational/vibronic spectroscopies are analyzed by Mirko Zerbetto, [12] Alfonso Pedone, [13] and Julien Bl...