New frontier of electronic structure calculations for strongly correlated molecular sciences from the fusion of deterministic and stochastic methodologies

2022 Fiscal Year Final Research Report

• Project/Area Number: 18H03900
• Research Category: Grant-in-Aid for Scientific Research (A)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Medium-sized Section 32:Physical chemistry, functional solid state chemistry, and related fields
• Research Institution: Kobe University
• Principal Investigator: Ten-no Seiichiro 神戸大学, 科学技術イノベーション研究科, 教授 (00270471)
• Project Period (FY): 2018-04-01 – 2022-03-31
• Keywords: 結合クラスター理論 / 量子モンテカルロ法 / 完全CI / 強電子相関 / スピン状態

Outline of Final Research Achievements

We implemented the full coupled-cluster (FCC) expansion to develop an adaptive FCC reduction (FCCR) approach using screenings for excitation manifolds and nonlinear CC operations. The second order perturbative correction using the FCCR reference (FCCR(2)) along with extrapolations efficiently provides near-exact solutions of strongly correlated electronic systems. We further attempted to mitigate the initiator error of configuration space QMC with respect to the system size using the ideas in CC and many-body perturbation theories. A powerful means from spin-projection including the treatment of dynamic correlation and second-order optimizer is also developed to treat transition metal complexes.

Free Research Field

電子状態理論

Academic Significance and Societal Importance of the Research Achievements

触媒やレドックス作用の重要な役割を担う電子相関の強い物質は、複雑な電子配置のために理論的な取り扱いが困難である。この問題の解決を目指して、決定論と確率論に基づく最先端の電子状態計算手法の開発を総合的に行った。得られた研究成果は理論の独創性と幅広い応用を持ち、基礎学問と社会的な双方の意義を備えている。