Development of Exact First-Principles GW+Bethe-Salpeter Method

2023 Fiscal Year Final Research Report

• Project/Area Number: 20K03784
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 13010:Mathematical physics and fundamental theory of condensed matter physics-related
• Research Institution: Shizuoka University
• Principal Investigator: Noguchi Yoshifumi 静岡大学, 工学部, 准教授 (60450293)
• Project Period (FY): 2020-04-01 – 2024-03-31
• Keywords: 第一原理 / GW近似 / Bethe-Salpeter方程式 / 励起子

Outline of Final Research Achievements

Considering full GW electron-hole interaction kernel, we developed first-principles GW+Bethe-Salpeter method and implemented it in our original all-electron mixed basis program. We applied our method to 26 typical organic molecules and investigated the contribution of the full GW electron-hole interaction kernel. We found that our method has different contributions for different types of excitons. These results were published in Phys. Rev. B, 106, 045113 (2022).
In addition, we applied our method to some inter- and intra molecular charge transfer excitations as well and revealed that the contributions of the full GW electron-hole interaction kernel are negligible small for inter-molecular charge transfer excitations however significant for intra-molecular charge transfer excitations. These results were published in J. Chem. Phys., 159, 234105 (2023).

Free Research Field

物性理論

Academic Significance and Societal Importance of the Research Achievements

1995年にOnidaらにより初めて第一原理GW+Bethe-Salpeter法が現実物質へ適応されて以来、今年でおよそ30年がたとうとしている。以来、実際の計算ではGW近似に加えてさらなる追加近似がGW電子-ホール相互作用核に対して陥られてきた。そのため、GW近似の範囲でも「厳密」に解放するには至っていないのが現状である。そこで本研究では追加近似を用いずに「完全な」GW電子-ホール相互作用核を計算することのできる新たな計算手法を開発し、いくつかの分子へ適応しその寄与の大きさを明らかにした。