Developments of electronic structure theories for excited states toward the understanding of the excitonic mechanism in organic aggregates

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K15231
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 32010:Fundamental physical chemistry-related
• Research Institution: Kobe University
• Principal Investigator: Tsuchimochi Takashi 神戸大学, システム情報学研究科, 准教授 (40763933)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: 量子化学

Outline of Final Research Achievements

While in molecular systems, there are several possible excited states, only a handful of them play a significant role in photochemistry. In this research, we have proposed computational methods that selectively calculate the excited states that are potentially important for photochemical processes. This allows us to clarify the characteristics of the target chemical reaction.
Furthermore, the wave functions obtained through these methods are utilized to construct an effective Hamiltonian, enabling a more precise description of complex excited states. Specifically, these methods have been developed to accurately describe electron spins, with the aim of achieving better correspondence with experimental results by eliminating unphysical spin-contaminated states.
Building upon these results, we have also developed excited state algorithms for quantum computers, establishing the groundwork for photochemical applications utilizing quantum devices.

Free Research Field

計算化学

Academic Significance and Societal Importance of the Research Achievements

分子内で起こる電子の励起状態をシミュレーションによって正確に追跡することにより、太陽光発電や人工光合成、あるいは光による異性化反応などの機構を解明することができる。本研究で開発したアプローチは計算コストと計算精度の両立を目指したものであり、これらを駆使することで多様な光化学シミュレーションを実行可能にすると考えられる。