Poster abstracts

Poster number 39 submitted by James Serna

Advancing Excited State Simulations in Biological Systems

James D. Serna (Biophysics Graduate Program), Alexander Yu. Sokolov (Department of Chemistry and Biochemistry, OSU)

Abstract:
Exposure to light induces a wide range of changes in biological molecules, driving both photodamage and essential photochemical functions. While radiation can lead to dysfunction through damage to proteins and DNA, it also enables critical biochemical processes in photoactive systems involved in enzymatic activity and cellular signaling. These processes proceed through electronically excited states, whose accurate description remains challenging due to their inherently quantum mechanical nature and complexity of biological systems and their environments. The hybrid quantum mechanical/molecular mechanical (QM/MM) approach is therefore essential for modeling these states, requiring accurate and balanced treatments of both the QM and MM regions. For the MM region, a strong choice is polarizable embedding (PE), which enables a mutual polarization response between the QM region and its environment. I will present work combining PE with accurate and efficient excited state methods developed in our group. Using algebraic diagrammatic construction (ADC) theory, I will describe results for ionized states in condensed-phase environments, highlighting the strong influence of polarization on ionization energies. Additionally, I will discuss initial results from combining PE with quasidegenerate N-electron valence perturbation theory (QD-NEVPT2), enabling the treatment of strongly correlated electronic states and their spectroscopic properties. These developments demonstrate the ability to simulate excited states in complex environments and provide a framework for studying light–matter interactions across a broad range of biologically relevant systems.

References:
Serna, J. D.; Sokolov, A. Y. J. Phys. Chem. A 2025, 129 (4), 1156–1167

Banerjee, S.; Sokolov, A. Y. J. Chem. Theory Comput. 2023, 19 (11), 3037–3053.

Angeli, C.; Borini, S.; Cestari, M.; Cimiraglia, R. A Quasidegenerate Formulation of the Second-Order N-Electron Valence State Perturbation Theory Approach. J. Chem. Phys. 2004, 121 (9), 4043–4049.

Keywords: Quantum chemistry, Light-matter interactions, Excited states