KEIO RESEARCHERS INFORMATION SYSTEM

Career 【 Display / hide 】

Career 【 Display / hide 】

• 2014.04

  -

  2016.06

  未利用熱エネルギー革新的活用技術研究組合 独立行政法人 産業技術総合研究所 (現 国立研究開発法人 産業技術総合研究所),  ナノシステム研究部門 （現 マテリアル DX 研究センター）, パートナー研究員

• 2016.07

  -

  2019.03

  名古屋大学大学院 , 情報科学研究科（現 情報学研究科）, ポスト「京」プロジェクト 博士研究員

• 2017.04

  -

  2019.03

  金城学院大学, 非常勤講師

• 2019.04

  -

  2020.03

  分子科学研究所, 日本学術振興会 特別研究員(PD)

• 2020.04

  -

  2023.03

  慶應義塾大学, 理工学部化学科, 助教(有期)

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Academic Background 【 Display / hide 】

Academic Background 【 Display / hide 】

• 2003.04

  -

  2007.03

  Kanazawa University, 理学部, 化学科

  University, Graduated

• 2007.04

  -

  2009.03

  Kyoto University, 理学研究科, 化学専攻

  Graduate School, Completed, Master's course

• 2009.04

  -

  2014.03

  Kyoto University, 理学研究科, 化学専攻

  Graduate School, Withdrawal after completion of doctoral course requirements, Doctoral course

Academic Degrees 【 Display / hide 】

Academic Degrees 【 Display / hide 】

• 博士(理学), Kyoto University, Coursework, 2014.05

  Theoretical Study on Mechanism and Dynamics of Hydrogen Transfer Reaction

Matters concerning Career Achievements 【 Display / hide 】

Matters concerning Career Achievements 【 Display / hide 】

• 2026.04

  -

  Present

  ポテンシャルスケーリング法に関する技術指導

Research Areas 【 Display / hide 】

Research Areas 【 Display / hide 】

• Nanotechnology/Materials / Fundamental physical chemistry (理論化学, 計算化学)

Research Keywords 【 Display / hide 】

Research Keywords 【 Display / hide 】

• 化学反応, 電子状態, 分子ダイナミクス

Research Themes 【 Display / hide 】

Research Themes 【 Display / hide 】

• 微小液滴における化学反応の加速機構の理論的解明, 

  2025.04

  -

  Present

• 振動分光スペクトル計算による不均一界面の分子論的解析, 

  2021.04

  -

  Present

• 凝縮系における複雑多段階反応の解析手法の開発と実在材料系への応用, 

  2020.04

  -

  Present

Books 【 Display / hide 】

Books 【 Display / hide 】

• 次世代自動車の熱マネジメント～車室内の温熱快適性・廃 熱利用技術～

  石田 豊和, 稲垣 泰一, 技術情報協会, 2020.12

  Scope: 第6 章 第6 節 “蓄熱材の蓄熱機構に関する計算化学からのアプ ローチ”

• マテリアルズ・インフォマティクスによる材料 開発と活用集

  石田豊和, 稲垣泰一, 馬場哲也, 技術情報協会, 2019.01

  Scope: 第4 章 第9 節 “計算科学と熱物性データベースを活用した高密度 蓄熱材の探索”

• 蓄熱システム/蓄熱材料実用化のポイント

  稲垣泰一, 石田豊和, S&T出版, 2018.01

  Scope: 第2 章 第11 節 “潜熱蓄熱材料の計算科学”

Papers 【 Display / hide 】

Papers 【 Display / hide 】

• An Approximate Method for Exploring Nonradiative Decay Pathways From Highly Excited States of Lanthanide Complexes: Application to Luminescent Cerium Complexes

  Ikuta S., Inagaki T., Hatanaka M.

  Journal of Computational Chemistry 47 ( 5 )  2026.02

  Research paper (scientific journal), Joint Work, Accepted,  ISSN  01928651

  　View Summary

  The exploration of minimum energy crossing points (MEXs) between potential energy surfaces (PESs) is essential for understanding nonradiative decay mechanisms and plays a key role in the design of photofunctional materials. In lanthanide (Ln³⁺) complexes, however, the presence of open-shell 4f^N electrons leads to quasi-degenerate electronic states, making MEX searches particularly challenging. To describe the PESs of 4f-5d or charge-transfer excited states (i.e., 4f^N−1X excited states) of Ln³⁺ complexes, we propose a new approximation, the ion energy shift (IES) method. In this approach, the 4f^N−1X excited state is represented using density functional theory (DFT) with the large-core relativistic effective core potential (RECP) for Ln⁴⁺, which has a higher formal charge than the actual ion (Ln³⁺), and the PES is shifted to reproduce the target excitation energy. In this study, we validate the IES method against the multiconfigurational wavefunction results and apply it to elucidate the origin of the different excited-state lifetimes of hydrated Ce³⁺ complexes with and without coordination of a carboxylate ligand.

  • Access to Document (DOI)

• Mechanistic origin of C- over O-glycosylation in glycosyltransferase GgCGT: a QM/MM study

  Terada D., Inagaki T., Hatanaka M.

  Bulletin of the Chemical Society of Japan 99 ( 2 )  2026.02

  Research paper (scientific journal), Joint Work, Accepted,  ISSN  00092673

  　View Summary

  C-glycosylation catalyzed by C-glycosyltransferases affords chemically robust C-glycosides, yet the mechanistic origin of the remarkable selectivity for C- over O-glycosylation remains poorly understood. In this study, we present a comprehensive QM/MM investigation of the GgCGT-catalyzed mono-C-glycosylation of phloretin using UDP-glucose, extending our previous cluster-model analysis to explicitly include the full enzymatic environment. The calculated pathway involves an initial proton transfer from phloretin to UDP-glucose, followed by an S<inf>N</inf>2-type C-glycoside bond forming step accompanied by dissociation of UDP. The activation barrier of the rate-determining S<inf>N</inf>2 step is in good agreement with the experimental estimates. Although the alternative O-glycosylation pathway exhibits a lower activation barrier, it is thermodynamically disfavored due to the instability of the O-glycosylated intermediate, which readily undergoes the reverse reaction. In contrast, the C-glycosylated intermediate is strongly stabilized, rendering C-glycosylation effectively irreversible. Structural and natural bond orbital analyses reveal that this stability originates from preservation of a planar His27-Asp122 dyad and a favorable hydrogen-bonding network involving the phosphate group. Furthermore, the C6-OH group of glucose directly stabilizes the key transition state, explaining the reduced reactivity observed experimentally with UDP-xylose. These results establish a dual catalytic strategy in C-glycosyltransferases, combining thermodynamic control for C-selectivity with transition-state stabilization for rate acceleration.

  • Access to Document (DOI)

• Comprehensive Molecular-Level Understanding of MgO Hydration through Computational Chemistry

  Inagaki T., Hatanaka M.

  Journal of Physical Chemistry C 130 ( 3 ) 1312 - 1326 2026.01

  Research paper (scientific journal), Joint Work, Lead author, Corresponding author, Accepted,  ISSN  19327447

  　View Summary

  The hydration of magnesium oxide (MgO) to magnesium hydroxide (Mg(OH)<inf>2</inf>) is a fundamental solid-surface chemical reaction with significant implications for materials science. Yet its molecular-level mechanism from water adsorption to Mg(OH)<inf>2</inf> nucleation and growth remains elusive due to its complex and multistep nature. Here, we elucidate the molecular process of MgO hydration based on structures of the MgO/water interface obtained by a combined computational chemistry approach of potential-scaling molecular dynamics simulations and first-principles calculations without any a priori assumptions about reaction pathways. The result shows that the Mg²⁺ dissolution follows the dissociative water adsorption. We find that this initial dissolution can proceed exothermically even from the defect-free surface with an average activation barrier of ∼12 kcal/mol. This exothermicity depends crucially on the stabilization of the resulting surface vacancy, achieved by proton adsorption onto neighboring surface oxygen atoms. Further Mg²⁺ dissolution then occurs in correlation with proton penetration into the solid. Moreover, we find that the Mg(OH)<inf>2</inf> nucleation and growth proceeds according to the dissolution–precipitation mechanism, rather than a solid-state reaction mechanism involving a direct topotactic transformation. In this process, Mg²⁺ ions migrate away from the surface and form amorphous Mg–OH chains as precursors for Mg(OH)<inf>2</inf> nucleation. We also demonstrate that sufficient water facilitates the formation of more ordered crystalline nuclei. This computational study provides a comprehensive molecular-level understanding of MgO hydration, representing a foundational step toward elucidating the mechanisms of this class of complex and multistep solid-surface chemical reactions.

  • Access to Document (DOI)

• Mechanistic elucidation of enzymatic C-glycosylation: facilitation by proton transfer to UDP-glucose

  Terada D., Inagaki T., Hatanaka M.

  Rsc Advances 15 ( 35 ) 28592 - 28600 2025.08

  Research paper (scientific journal), Joint Work, Accepted

  　View Summary

  C-Glycosyltransferases have garnered attention owing to their ability to synthesize C-glycosides with high conversion and selectivity in one-pot reactions. Their potential in rational enzyme engineering makes them valuable for the synthesis of diverse C-glycosides. However, the detailed reaction mechanism remains unclear. To address this, we investigated the C-glycosylation of phloretin catalyzed by the glycosyltransferase GgCGT in the presence of the coenzyme UDP-glucose. Using density functional theory (DFT) calculations on a cluster model, we identified the most favorable pathway for C-glycosylation. The reaction proceeds via an initial proton transfer from phloretin to UDP-glucose, followed by the nucleophilic attack of phloretin on the glucose moiety and subsequent dissociation of UDP in an S<inf>N</inf>2-like manner. The S<inf>N</inf>2 step yields a non-aromatic intermediate, which can be rapidly converted to C-glycoside even without an enzymatic environment. The key residue that facilitates the rate-determining S<inf>N</inf>2 step is His-27, which stabilizes phloretin via hydrogen bonding. Additionally, to clarify why alternative products such as O-glycosides are not formed, we also investigated the O-glycosylation pathway. Our calculations revealed that O-glycosylation was promoted by proton transfer from UDP-glucose, like C-glycosylation, but was suppressed by structural fixation due to hydrogen bonding among phloretin, glucose, and GgCGT.

  • Access to Document (DOI)

• Exploration of the Global Minimum and Conical Intersection with Bayesian Optimization

  Somaki R., Inagaki T., Hatanaka M.

  Molecular Informatics 44 ( 2 )  2025.02

  Research paper (scientific journal), Accepted,  ISSN  18681743

  　View Summary

  Conventional molecular geometry searches on a potential energy surface (PES) utilize energy gradients from quantum chemical calculations. However, replacing energy calculations with noisy quantum computer measurements generates errors in the energies, which makes geometry optimization using the energy gradient difficult. One gradient-free optimization method that can potentially solve this problem is Bayesian optimization (BO). To use BO in geometry search, an acquisition function (AF), which involves an objective variable, must be defined suitably. In this study, we propose a strategy for geometry searches using BO and examine the appropriate AFs to explore two critical structures: the global minimum (GM) on the singlet ground state (S<inf>0</inf>) and the most stable conical intersection (CI) point between S<inf>0</inf> and the singlet excited state. We applied our strategy to two molecules and located the GM and the most stable CI geometries with high accuracy for both molecules. We also succeeded in the geometry searches even when artificial random noises were added to the energies to simulate geometry optimization using noisy quantum computer measurements.

  • Access to Document (DOI)

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Papers, etc., Registered in KOARA 【 Display / hide 】

Papers, etc., Registered in KOARA 【 Display / hide 】

• Theoretical elucidation of molecular collective structures triggering water autoionization

  Inagaki, Taichi

  学事振興資金研究成果実績報告書 (慶應義塾大学)  2021

• Theoretical elucidation of molecular collective structures triggering water autoionization.

  Inagaki, Taichi

  学事振興資金研究成果実績報告書 (慶應義塾大学)  2020

Reviews, Commentaries, etc. 【 Display / hide 】

Reviews, Commentaries, etc. 【 Display / hide 】

• ポテンシャルスケーリングを導入したハイブリッドモンテカルロ法： 多峰性カノニカル分布と緩和過程

  稲垣 泰一

  分子シミュレーション学会誌 “アンサンブル” 24 ( 2 ) 115 - 121 2022.04

  Article, review, commentary, editorial, etc. (scientific journal), Single Work, Lead author

Presentations 【 Display / hide 】

Presentations 【 Display / hide 】

• 固体表面における複雑多段階化学反応の理解を目指した分子シミュレーション研究

  稲垣 泰一

  [Domestic presentation]  研究会 「凝縮系の構造・反応ダイナミクスから機能創発への展開」, 

  2025.10

  , 

  Oral presentation (invited, special)

• 分子シミュレーションと第一原理計算による酸化マグネシ ウムの水和機構の解明

  稲垣 泰一, 畑中 美穂

  [Domestic presentation]  第19 回分子科学討論会, 

  2025.09

  , 

  Oral presentation (general)

• 理論・計算・シミュレーションによる化学現象の分子論的理解と創造

  稲垣 泰一

  [Domestic presentation]  豊田理研異分野若手交流会, 

  2025.09

  , 

  Poster presentation

• Molecular insights into the hydration reaction of magnesium oxide

  Taichi Inagaki, Miho Hatanaka

  [International presentation]  The Molecular Quantum Mechanics Conferences (MQM) 2025, 

  2025.05

  , 

  Poster presentation

• 酸化マグネシウムの水和機構に関する計算化学的研究

  稲垣 泰一, 畑中 美穂

  [Domestic presentation]  日本化学会 第105 春季年会, 

  2025.03

  , 

  Oral presentation (general)

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Research Projects of Competitive Funds, etc. 【 Display / hide 】

Research Projects of Competitive Funds, etc. 【 Display / hide 】

• 溶媒和と揺らぎに着目した空気-水界面の化学反応加速機構の理論的解明

  2025.04

  -

  2029.03

  基盤研究(C), Principal investigator

• Molecular Dynamics Unravels the Microwave-Specific Effect Accelerating Chemical Reactions

  2025.04

  -

  2026.03

  公益財団法人 豊田理化学研究所, 豊田理研スカラー, Research grant, Principal investigator

• 高次非線形分光計算による界面水物性の分子論的解析

  2022.04

  -

  2023.03

  分子科学研究所, 共同利用研究, Research grant, Principal investigator

• 分子シミュレーションで探る化学蓄熱の分子論的な律速過程と反応性向上への道

  2021.04

  -

  2025.03

  MEXT,JSPS, Grant-in-Aid for Scientific Research, Grant-in-Aid for Early-Career Scientists , Principal investigator

• 水の自己イオン化を引き起こす分子集団構造の理論的解明

  2021.04

  -

  2022.03

  慶應義塾大学, 学事振興資金 個人研究 C, Research grant, Principal investigator

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Awards 【 Display / hide 】

Awards 【 Display / hide 】

• 日本化学会 第98 春季年会 優秀講演賞（学術）

  2018.03, 日本化学会, イオン液体による金電極のポテンシャルシフトのメカニ ズム: 界面電荷移動の重要な役割

  Type of Award： Award from Japanese society, conference, symposium, etc.

• 第６回分子科学討論会（東京）2012 分子科学会優秀ポスター賞

  2012.09, 分子科学会, 溶液内水素移動反応のトンネリング効果:ユビキノール-ビタミンEの抗酸化反応

  Type of Award： Award from Japanese society, conference, symposium, etc.

Courses Taught 【 Display / hide 】

Courses Taught 【 Display / hide 】

• LABORATORIES IN BASIC CHEMISTRY

  2026

• LABORATORIES IN CHEMISTRY 1

  2026

• PHYSICAL CHEMISTRY EXERCISE 2

  2026

• PHYSICAL CHEMISTRY EXERCISE 1

  2026

• PHYSICAL CHEMISTRY EXERCISE 2

  2025

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Courses Previously Taught 【 Display / hide 】

Courses Previously Taught 【 Display / hide 】

• 情報リテラシー

  金城学院大学

  2017.04

  -

  2019.03

  , 

  Spring Semester, Undergraduate (liberal arts), Lecture, Within own ｆaculty

Educational Activities and Special Notes 【 Display / hide 】

Educational Activities and Special Notes 【 Display / hide 】

• 化学実験第Ⅰ 2026 10. 量子ダイナミクス

  2026.04

  , Development of Textbook and Teaching Material

• 化学実験第Ⅰ 2021 9. 量子化学Ⅰー単純Huckel法

  2021.04

  , Development of Textbook and Teaching Material

Media Coverage 【 Display / hide 】

Media Coverage 【 Display / hide 】

• 三菱ケミカルなど、量子コンピュータを用いた光機能性物質向け計算法を開発

  2023.02

Academic Activities 【 Display / hide 】

Academic Activities 【 Display / hide 】

• 科学技術予測・政策基盤調査研究センター 専門調査員

  2025.06

  -

  Present

• 第37回分子シミュレーション討論会 学生優秀発表賞（ポスター）審査委員

  2023.12

• 2023年分子科学討論会優秀優秀ポスター賞選考委員（理論・計算）

  2023.09

• 第16回分子科学討論会2022横浜実行委員会

  2022.09

• シンポジウム「化学反応経路探索のニューフロンティア2022」世話人

  2022.09

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Memberships in Academic Societies 【 Display / hide 】

Memberships in Academic Societies 【 Display / hide 】

• The Molecular Simulation Society of Japan, 

  2021

  -

  Present

• The Physical Society of Japan, 

  2019

  -

  Present

• 日本潜熱工学会, 

  2019

  -

  Present

• The Chemical Society of Japan, 

  2014

  -

  Present

• Japan Society for Molecular Science, 

  2012

  -

  Present

Committee Experiences 【 Display / hide 】

Committee Experiences 【 Display / hide 】

• 2024.10

  -

  2025.09

  分子科学会 総務委員 分子科学会速報配信主担当

• 2023.10

  -

  Present

  慶應義塾大学 学生総合センター委員

• 2023.10

  -

  2024.09

  分子科学会 総務委員 分子科学会速報配信副担当