Challenges of Quantum Chemistry in Solvent from Electronically Excited DNA to Polarizable Continuum Models

Adrian Lange
Seminar

Quantum chemistry is extremely accurate and easily applicable in gas phase molecular systems. However, the same accuracy and ease is not always enjoyed when applying quantum chemistry to condensed phase systems, such as molecules dissolved in solvent. In this presentation, we discuss our efforts in modeling solution phase chemistry and the difficulties we have had to overcome in order to do so. For example, we analyze spurious charge transfer contamination in Time Dependent Density Functional Theory (TD-DFT) and how it can be ameliorated with long-range corrected functionals, such as LRC-wPBE. We then discuss the application of this functional to understanding excited electronic states of aqueous DNA, including its exciton and charge transfer states. In addition, we present several recent advances in the theory and computation of polarizable continuum models (PCMs) for implicit solvation, which are commonly used in quantum chemistry calculations. We discuss failures of traditional PCM methodology, our approach for rectifying these failures, our newly derived PCM for solving the linearized Poisson-Boltzmann equation, and our linear scaling parallel implementation of PCM for large solute molecules.