Computational and Conceptual Density Functional Theory for Electronic Resonances.

Temporary anions are metastable states embedded in the detachment continuum that are formed upon electron attachment to molecules whose electron affinity is negative. These are electronic resonances that cannot be described using standard electronic structure methods. This project comprises computational and conceptual developments for these challenging systems. To this end, the electronic structure of temporary anions will be studied by both density functional theory with artificial binding techniques and, as an alternative, with non-Hermitian complex-variable techniques. Exploiting the intrinsically low computational cost of density functional theory, these new electronic-structure methods will enable the study of temporary anions in large molecular systems that are beyond the reach of wave function-based methods. Next, we will connect our computational results to classical chemical concepts and analyze changes in bonding and chemical reactivity induced by electron attachment within the framework of quantum chemical topology and conceptual DFT. Specifically, we will use our new methods to analyze microsolvation of anions that are metastable in gas phase. Here, we aim to establish solvation limits for chemical quantities. In addition, we will study DNA fragments and analyze the reaction mechanisms by which attachment of slow electrons to the nucleobases leads to strand breaks in the sugar backbone.