Simulating electronic excitation induced proton transfer in heterogeneous environments

Excited-state intramolecular proton transfer (ESIPT) is one of the essential steps in solar energy conversion by many biological and chemical systems. In order to investigate such key dynamical processes from first principles, we newly developed a periodic real-time nuclear-electronic orbital time-dependent density functional theory (RT-NEO-TDDFT) method such that proton dynamics are treated quantum mechanically. In this work,we study how atomistic environments like water solvation and the presence of a material surface affect electron excitation-induced proton transfer in the o-hydroxybenzaldehyde (oHBA) molecule. Competing kinetics between electronic excitation dynamics and quantum-mechanical proton transfer are discussed as an example of how such a new multicomponent DFT formulation can expand the application of RT-TDDFT.