Our research is dedicated to theoretical understanding of novel electronic, optical, and magnetic properties of materials, in terms of their microscopic properties, namely, composition and structure. To that end, we use first principles calculations, i.e., calculations where material properties are predicted from nothing more than the atomic number and mass of the atomic species involved, based on the laws of quantum physics.
We pursue the first principles approach because we believe that whenever a truly new class of materials and/or material structures emerges, theoretical analyses based on phenomenology, simplified models, or just good-old “physical and chemical intuition” may initially face significant difficulties. The reason is that the observed physical and/or chemical phenomena often simply cannot be explained by the traditional models. Instead, new understanding and “intuition” must gradually evolve. These are, naturally, first and foremost guided by experiment. But when the materials are not sufficiently well controlled or characterized, using experiment alone as a guide could be highly misleading. This clearly calls for a first principles theory. It is used to confirm, explain, and ultimately predict new phenomena, and serves as a solid foundation on which new intuition and phenomenology can be built.
Our first principles calculations are usually based on density functional theory (DFT), but we also employ many-body perturbation theory (MBPT) and tight binding (TB) models. We are mostly interested in experimentally accessible properties of real materials (as opposed to model systems). Therefore, much of the work is performed in close interaction with pertinent experimental groups and enjoys the synergy inherent in such collaborations.
Naturally, attacking cutting-edge materials science research problems using computational tools necessarily involves using the best possible methodology in both the formal and numerical aspects of the computation. We are therefore heavily involved in methodological work. We view the combination of research into materials and methodological issues as essential to the research. It allows us to use materials research questions as concrete “drivers” for further formal and computational methodological developments, which, in turn, allow us to reach into an ever-increasing array of previously unexplored materials science questions.
In our materials research, we presently focus on organic electronic materials, including organic-inorganic hybrids and interfaces, as well as supra-molecular materials. We also have a long-standing interest and expertise in nano-materials, spintronics and molecular electronics. Our studies emphasize the understanding of collective phenomena, namely, properties which arise from non trivial interactions between different components of the material or structure. On the formal side, we pursue orbital-dependent density functionals. These often allow for unprecedented accuracy in calculations based on density functional theory - the "work horse" behind most of our computations. In particular, we are developing optimally tuned range-separated hybrid functionals as a tool for spectroscopy. On the computational side, we specialize in grid-based real-space first principles approaches, because these can relatively easily be used to treat large-scale systems and because they can be well-suited to calculations with orbital-dependent density functionals.