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O: Fachverband Oberflächenphysik
O 82: Poster Session VI: Poster to Mini-Symposium: Frontiers of electronic-structure theory III
O 82.4: Poster
Wednesday, March 3, 2021, 13:30–15:30, P
Optimized effective potentials to increase the accuracy of approximate proton transfer energy calculations in the excited state — •Pouya Partovi-Azar and Daniel Sebastiani — Institute of Chemistry, MLU Halle-Wittenberg, Halle (Saale), Germany
In various systems, acidic properties emerge when the system is electronically excited. Although the time scale attributed to the dynamics of the electrons is usually on the order of femtoseconds, the electronic excitations can in general trigger much slower processes.
Here, we propose and benchmark a novel approximate first-principles molecular dynamics simulation idea for increasing the computational efficiency of density functional theory-based calculations of the excite states. We focus on obtaining proton transfer energy at the S1 excited state through actual density functional theory calculations at the T1 state with additional optimized effective potentials. The potentials are optimized such as to reproduce the time-dependent density functional theory energy surface, but can be generalized to other more accurate quantum chemical methods. We demonstrate the applicability of this method for two prototypical photoacids, namely phenol and 7-hydroxyquinoline. We show that after optimizing the additional effective potentials for carbon, nitrogen, oxygen, and the acidic hydrogens, both thermodynamics and kinetics of proton dissociation reaction can be well reproduced as compared to reference excited-state calculations. It is found that a good agreement can be reached by only optimizing two effective potential parameters per each species in the photoacids.