In molecular and material science, modeling and computer simulation have gained a central role thanks to the exponential growth of computing power delivered by modern computers paralleled by similarly significant advances in theoretical methods and algorithms. Therefore, molecular modeling is currently employed for (i) understanding the properties of materials at the atomistic and molecular level; (ii) identifying and rationalizing the fundamental chemical processes which mimic complex environments such as surfaces and heterointerfaces; (iii) guiding the synthesis and production of new materials via molecular design; (iv) designing and optimizing nanosystems for a variety of applications ranging from electronics to energy conversion and storage to the development of materials with specific target properties. Nowadays high-performance computers permit the theoretical study of systems of large dimensions and increasing complexity with unprecedented accuracy.

The main research topic of our group deals with the use of theoretical simulations to the study of Dye-Sensitized Solar cells (DSC) and Organic Light-Emitting Diodes (OLED) both representing valuable examples of the “green revolution” which is driving the world economy towards a sustainable growth on a grand scale. A major difficulty in the theoretical and computational simulation of transition metal complexes and nano-structured materials resides is the inherent complexity of the systems under investigation. The complex interatomic interactions underlying these systems call for the use of accurate computational techniques, while the large dimensions of these systems substantially limit the accuracy of the computational tools which can be employed. Even computational tools showing a reasonable compromise between their accuracy and computational overhead, still have to tackle the inherent complexity of systems composed by several hundred (thousand) atoms, which usually show a large number of relevant geometrical configurations. The situation is even more severe if one considers properties related to excited states, such as those we are dealing with in DSC, OLED and materials for NLO. To solve this very challenging issue, we have over time set up an integrated computational strategy based on a combination of different codes and techniques rooted on Density Functional Theory (DFT).