Title: Nuclear Quantum Effect on Electronic Excitation in Hydrogen-bonded Organic Solids: First-Principles Many-Body Theory StudyOral: Nuclear Quantum Effect on Electronic Excitation in Hydrogen-bonded Organic Solids: First-Principles Many-Body Theory Study

While nuclear quantum effects are crucial for accurately describing the structure of hydrogen-bonded systems such as water, their impact on electronic excitations remains largely unexplored. Proton quantum effects play a significant role in the electronic excited states of organic materials with extensive hydrogen bonds. Using 5,6-dihydroxyindole (DHI), a building block of Eumelanin, we examine how proton quantization affects electronic excitation through first-principles many-body theory. Specifically, we treat protons in hydrogen bonds quantum mechanically using the nuclear-electronic orbital (NEO) and Green’s function calculation (-BSE) was performed. This study examines the extent to which proton quantization impacts electronic excitations and how in a prototypical organic material in which hydrogen bonds play a key role.