Ten Years Developing Electronic Structure Methods at the DIPC

In this talk, I will present an overview of our group’s research at the DIPC over the past decade, tailored for a broad, non-specialist audience. Our work is rooted in quantum chemistry and spans three interconnected research areas: electron correlation, molecular properties, and aromaticity. Electron correlation, a cornerstone of quantum chemistry, serves as the foundation for developing new electronic structure methods. I will highlight our recent efforts to create tools for assessing electron correlation. These tools are critical for constructing large datasets used in high-throughput screening and for designing correlation-tailored electronic structure methods that outperform their standard counterparts. Our group also investigates the computation of molecular properties, including linear and nonlinear optical properties —areas that pose significant challenges for most electronic structure methods, especially density functional theory (DFT). Recently, we identified a major deficiency in the simulation of molecular properties using density functional approximations (DFAs). This intrinsic error affects the construction of many DFT functionals, with implications extending beyond molecular properties. In response, we have developed new DFAs that address this issue. Finally, we will explore the concept of aromaticity, linking it to the broader notion of electron delocalization. I will discuss how our focus has shifted from studying molecular aromaticity to examining electron delocalization in macrocycles, small clusters, and, ultimately, extended structures.