Yabushita, Satoshi

写真a

Affiliation

Faculty of Science and Technology (Mita)

Position

Professor Emeritus

External Links
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Other Affiliation 【 Display / hide 】

  • 慶應義塾大学理工学研究科, 基礎理工学専攻, 基礎理工学専攻人事委員会委員長(2016年4月～ 2018年3月)

  • 慶應義塾大学理工学研究科, 基礎理工学専攻, 基礎理工学専攻専攻長(2014年4月～ 2016年3月)

  • 慶應義塾大学理工学部, 化学科, 化学科主任(2008年4月～ 2012年3月)

  • 慶應義塾大学理工学研究科, 基礎理工学専攻分子化学専修, 分子化学専修主任(2007年4月～ 2009年3月)

  • 慶應義塾大学理工学部, 化学科, 学習指導副主任(2003年4月～ 2007年3月)

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Career 【 Display / hide 】

  • 1982.08
    -
    1983.12

    米国北ダコタ州立大学化学科 ,博士研究員

  • 1984.01
    -
    1986.09

    米国オハイオ州立大学化学科 ,博士研究員

  • 1986.09
    -
    1988.03

    分子科学研究所（理論系） ,技官

  • 1988.04
    -
    1993.03

    広島大学（理学部） ,助手

  • 1993.04
    -
    1994.03

    千葉大学（教養部） ,助教授

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Academic Background 【 Display / hide 】

  • 1973.04
    -
    1977.03

    Osaka University, Faculty of Engineering Science, Department of Chemical Engineering

    University, Graduated

  • 1979.03

    Osaka University, Graduate School, Division of Engineering Science, 化学系専攻

    Graduate School, Completed, Master's course

  • 1982.03

    Osaka University, Graduate School, Division of Engineering Science, 化学系専攻

    Graduate School, Completed, Doctoral course

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Academic Degrees 【 Display / hide 】

  • 工学　, Osaka University, 1982.03

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Research Areas 【 Display / hide 】

  • Nanotechnology/Materials / Fundamental physical chemistry

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Research Keywords 【 Display / hide 】

  • Theoretical Chemistry Quantum Chemistry

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Research Themes 【 Display / hide 】

  • 希土類イオン、希土類化合物の光応答特性の理論研究, 

    1993.04
    -
    Present

  • Quantum chemical study of heavy element systems with spin-orbit configuration interaction methods, 

    1986.10
    -
    Present

    　View Summary

    Using the spin-dependent unitary group approach, the time-reversal symmetry, and double group symmetries, we have developed highly efficient spin-orbit configuration interaction method including relativistic effects for quantum chemical calculations of various molecular systems. We have applied particularly to nonadiabatic processes in chemical reactions in electronic excited states and/or at dissociation regions.

  • Theoretical study of molecular resonance states and photoionization processes, 

    1984.01
    -
    Present

    　View Summary

    We are also developing the complex coordinate method for resonance states appearing in electron-molecule systems and molecular photoionizations in intense laser fields.

  • Theoretical study of intramolecular electron density migrations through vibrational intensities of X-H bonds, 

    1981.04
    -
    Present

    　View Summary

    We are constructing a theory to explain the interesting behavior of overtone vibration intensity of simple molecules based on the local mode picture.

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Books 【 Display / hide 】

  • ライフコンジュゲートケミストリー

    YABUSHITA SATOSHI, 2006.10

    Scope: 289-303

  • 日本化学会編、第５版 実験化学講座１２

    YABUSHITA SATOSHI, 丸善, 2004.03

    Scope: 225-235

  • 日本化学会編、第５版 実験化学講座１２

    YABUSHITA SATOSHI, 丸善, 2004.03

    Scope: 81-87

  • 物理化学演習

    伊藤正時、大場茂、茅幸二、仙名保、中嶋敦、藪下聡, 裳華房, 1999.01

    Scope: 59-103

    　View Summary

    慶應義塾大学理工学部１年生の共通必須科目「化学A」の教科書、及びその他関連科目の参考書として、共同執筆。第４章「分子軌道と化学結合」を担当した。

  • Relativistic Effects on Transition State Structures and Properties

    藪下聡, in 'The Transition State - A Theoretical Approach', edited by T.Fueno, Gordon & Breach Scientific Pub., 1999

    Scope: 267-281

    　View Summary

    重原子を含む化学反応の遷移状態の構造や活性化エネルギーなどに相対論がどのような影響を及ぼすかを議論したもの。特にIHI 、IHBrが遷移状態になる場合、その負イオンの光電子スペクトルから実験的な詳細な情報が得られるが、それに対して理論計算の結果を比較した。また奇数電子系のスピン軌道CI計算法の概説を行った。

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Papers 【 Display / hide 】

  • Size-Dependent π<inf>g</inf>+ π<inf>u</inf>Combination Band Intensities of Polyynes C<inf>2 n</inf>H<inf>2</inf>(n = 1-9) Analyzed by the Local CCH Bending and the Linear Response Functions

    Tsuyuki M., Kugaya Y., Kanamori H., Yabushita S.

    Journal of Physical Chemistry A (Journal of Physical Chemistry A)  125 ( 29 ) 6404 - 6419 2021.07

    ISSN  10895639

    　View Summary

    Polyynes (C2nH2) show the unusually strong πg + πu combination bands in the infrared absorption spectra. We calculated them as the first overtone of the local CCH bending; the strong intensities are interpreted as a consequence of the large-amplitude bending vibration of the acidic acetylenic hydrogen combined with the size-dependent πelectron conjugation. Our theoretical calculations show that the absorption intensity increases steadily and their increase rate is gradually slowed down by increasing the number of acetylene units up to n = 9. However, the calculated vibrational wavenumber converges quickly in agreement with the experimental observation. The second-order electron density deformation caused by the local CCH bending was analyzed using the linear response functions, including the linear and nonlinear contributions, to explain the n dependence. The easily polarizable πelectron density caused two kinds of deformation - dominant but dark δxx-yy type and minor but bright σ type. Both of them exhibit interesting zigzag sign alternations, consistent with the law of alternating polarity of Coulson and Longuet-Higgins. The electron density polarization in these intra- and interacetylene units induces a large axial component molecular dipole moment, contributing to the intensity that increases with n. The difference between the curvilinear and rectilinear bending coordinates is interpreted within the present theoretical scheme.

  • Graphical transition moment decomposition and conceptual density functional theory approaches to study the fundamental and lower-level overtone absorption intensities of some OH stretching vibrations

    Tsuyuki M., Furudate S., Kugaya Y., Yabushita S.

    Journal of Physical Chemistry A (Journal of Physical Chemistry A)  125 ( 10 ) 2101 - 2113 2021.03

    ISSN  10895639

    　View Summary

    The investigation of electron density migrations caused by molecular structure changes is of central importance in various fields of chemistry. To address this topic in general and to study absorption intensities of vibrations, we analyze sensitive dipole moment functions (DMFs) of a molecule by combining the linear response function of conceptual DFT and bond dipoles separated by the quantum theory of atoms in molecules with a graphical transition moment decomposition scheme. The fundamental intensities of OH stretching vibrations depend strongly on the substituents but only weakly on the molecular conformations. Interestingly, in some alcohols, completely opposite trends have been observed for the lower-level overtone intensities: a weak substituent dependence but a stronger conformation dependence. It is well known that the formation of a hydrogen-bonded complex increases the OH stretching fundamental intensity, but less well known is the decrease in their overtone intensities. To investigate these characteristics comprehensively, we calculated their intensities (Δv = 1, 2, and 3) for conformers of ethanol and trifluoroethanol (TFE) and hydrogen-bonded phenol (PhOH) systems via the DFT method in the local mode model for the OH stretching coordinate ΔR. Their first and second derivatives of the electron density with respect to ΔR were calculated and interpreted using their bond moments. For ethanol and TFE, the OH, CC, and CH bond moments were found to make an important contribution to the molecular DMF derivatives parallel to the OH bond. The OH bond contributes only to the first derivative of DMF, and its conformational dependence is determined by the magnitude of the charge polarization of each structure. The electron density derivatives in the CC bond region were largely maintained during the internal rotation; thus, their conformation-dependent contributions were expressed by a geometrical factor of the CC bond direction. The CH bond at the antiperiplanar position of the OH bond was found to make a remarkably large contribution to the second derivative of DMF in the gauche conformer. The importance of electron density migration on substituents was also identified in the hydrogen-bonded phenol, in which the π-electron density change on the aromatic ring was clearly shown. This migration creates the DMF derivatives both perpendicular and parallel to the OH bond and strongly affects the absorption intensities. In all the cases, some bond moments on the substituents contribute to the first and second DMF derivatives in a structure-dependent manner, thus explaining their stereoelectronic effects.

  • K-shell photoionization cross sections of one-electron uranium cation by relativistic complex basis function method

    Naoto Furuhashi, Satoshi Yabushita

    Journal of Physics B: Atomic, Molecular and Optical Physics (IOP Publishing Limited)  53 ( 12 )  2020.03

    Research paper (scientific journal), Joint Work, Accepted,  ISSN  09534075

    　View Summary

    The complex basis function (CBF) method is a square-integrable (L 2) function method that represents continuum wave functions, and has been applied successfully to various problems, including the calculation of resonance state energies and photoionization cross sections. The previous applications of this method have been limited to non-relativistic problems, and no serious attempt has been made for the relativistic Hamiltonian. In this study, we calculated the photoionization cross sections from the imaginary part of the frequency-dependent polarizability by applying the CBF method to the inhomogeneous Dirac equation of the one-electron uranium cation. The results obtained by employing a pure Coulomb potential to the K-shell photoionization cross sections were in good agreement with previous theoretical values and experimental values for the neutral uranium atom. Phase shifts were obtained by matching the CBF solutions with the numerical ones, which were further propagated by the fourth-order Runge–Kutta method, and thus, the photoionization differential and total cross sections were successfully calculated. The calculated results were analyzed from various viewpoints, including the multipole effect of electromagnetic fields, momentum conservation of photon and photoelectron, interference of multiple perturbation terms, and difference in the orbital angular momentum of the small component wave functions. These analyses demonstrate the effectiveness of the CBF method for the inhomogeneous Dirac equation and thus its applicability to multielectron systems.

  • Ab initio investigation on the IOOBr isomers and reaction pathways of the IO+BrO Reaction

    Tapas K. Ghosh, Satoshi Yabushita

    International Journal of Research in Chemistry and Environment (IJRCE) 9 ( 4 ) 1 - 9 2019.10

    Research paper (scientific journal), Joint Work, Accepted,  ISSN  2248-9649

    　View Summary

    Various minimum energy geometries, transition state geometries and possible reaction pathways have been investigated at the ab initio level of theories for the atmospheric important reaction between IO and BrO radicals. We employed SDB (Stuttgert-Dresden-Bonn)-cc-pVTZ basis sets for bromine and iodine and cc-pVTZ basis set for oxygen augmented with a set of diffuse functions (s,p) for each atom. The geometries and energetics have been studied at the MP2 and QCISD(T)//MP2 levels of theory, respectively. Possible reaction pathways for different product channels have been discussed on the basis of structural information and energetics along with results of the IRC calculations.

  • Importance of the Parallel Component of the Transition Moments to the 1Pi1 (5A’) and 3Pi1 (3A’) Excited States of ICN in the Ȃ-band Photodissociation

    Tatsuhiko Kashimura, Yabushita Satoshi.

    Journal of Physical Chemistry A (The American Chemical Society)  123 ( 18 ) 4000 - 4013 2019.04

    Research paper (scientific journal), Joint Work, Accepted,  ISSN  10895639

    　View Summary

    Copyright © 2019 American Chemical Society. ICN is one of the few simple triatomic molecules whose photodissociation mechanisms have been thoroughly investigated. Since it has a linear structure in the electronic ground state, the dissociation follows a photoexcitation at a linear or slightly bent structure. It is generally believed that the Ã-band consists of the dominant excitation to 3 Π 0+ (4A′) with the transition dipole moment (TDM) parallel to the molecular axis (z), a slightly weaker transition to 1 Π 1 (5A′, 4A″), and a much weaker transition to 3 Π 1 (3A′, 2A″), both of the latter two having perpendicular TDMs. In the present work, we have theoretically studied the geometry dependence of these TDMs and found a pronounced θ (bending angle) dependence in the parallel (z) component of the TDMs to 1 Π 1 (5A′) and 3 Π 1 (3A′), both of which should be zero at a linear geometry by symmetry and thus have been previously ignored. We estimated that the z component TDM to 1 Π 1 (5A′) has a contribution of 15-20% to the total absorption cross-section at 249 nm at room temperature. Interestingly, the TDM to 3 Π 0+ (4A′) does not exhibit such θ dependency and thus has only the z component. We compare the TDMs of ICN and CH 3 I molecules having similar excited states. The fact that all the TDMs to 3A′, 4A′, and 5A′ have nonnegligible z components implies the importance of the coherent excitation contributions to various observables of CN fragment, such as the anisotropy parameter, the orientation parameter, and the rotational level distribution as well as the rotational fine structure level distribution.

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

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Reviews, Commentaries, etc. 【 Display / hide 】

  • 理論化学会・将来構想委員会活動報告書

    藪下聡, 鷹野景子, 波田雅彦, 内田雅人, 庄司光男, 清野淳司, 中田彩子, 村岡梓, 横川大輔

    理論化学会誌 フロンティア (理論化学会)  3 ( 3 ) 182 - 203 2021.07

    Other, Joint Work

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Presentations 【 Display / hide 】

  • Coupled perturbed Kohn-Sham方程式および線形応答理論による電子密度の核座標微分

    藪下聡, 久賀谷有人, 露木雅文

    第１７回分子科学討論会 (大阪大学豊中キャンパス, 豊中、大阪) , 

    2023.09
    , 

    Poster presentation, 分子科学会

  • On the applicability of the CPKS equations without basis function derivative terms to the IR intensities of CH and OH vibrations

    Satoshi Yabushita

    TACC2023 (The 5th Conference of Theory and Applications of Computational Chemistry) (Institute for the Advancement of Higher Education, Hokkaido University, Sapporo, Japan) , 

    2023.09
    , 

    Oral presentation (invited, special)

  • Vibrational Absorption Intensities Studied by the Linear and Nonlinear Response Functions

    Satoshi Yabushita

    APATCC-10 (The 10th Conference of the Asia Pacific Association of Theoretical and Computational Chemists (International Centre for Interdisciplinary Science and Education ICISE, Quy Nhon, Vietnam) , 

    2023.02
    , 

    Oral presentation (invited, special), The Asia Pacific Association of Theoretical and Computational Chemists

  • Photoionization Cross Sections Calculated by the Complex Basis Function Method

    Satoshi Yabushita

    IWP-RIXS 2022 (International Workshop on Photoionization (IWP) Resonant Inelastic X-ray Scattering (RIXS) 2022 (Zao, Miyagi, Japan) , 

    2022.11
    , 

    Poster presentation

  • Coupled perturbed Kohn-Sham/Hartree-Fock方程式における非同次項の表式

    藪下聡, 久賀谷有人, 露木雅文

    第１６回分子科学討論会 (慶應義塾大学矢上キャンパス、横浜) , 

    2022.09
    , 

    Poster presentation, 分子科学会

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

  • Development and applications of theoretical computational methods for molecular response properties

    2020.04
    -
    2024.03

    MEXT,JSPS, Grant-in-Aid for Scientific Research, Grant-in-Aid for Scientific Research (C), Principal investigator

  • 原子・分子の共鳴状態および光イオン化過程の理論研究

    2016.04
    -
    2019.03

    MEXT,JSPS, Grant-in-Aid for Scientific Research, Grant-in-Aid for Scientific Research (C), Principal investigator

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Awards 【 Display / hide 】

  • 義塾賞

    藪下　聡, 2019.11, 慶應義塾, 理論化学に立脚した化学現象の原理的理解の深化

    Type of Award： Keio commendation etc.

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Courses Taught 【 Display / hide 】

  • THEORETICAL MOLECULAR CHEMISTRY

    2022

  • THEORETICAL MOLECULAR CHEMISTRY

    2021

  • THEORETICAL MOLECULAR CHEMISTRY

    2020

  • PHYSICAL CHEMISTRY 1

    2019

  • PHYSICAL CHEMISTRY 3

    2019

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Courses Previously Taught 【 Display / hide 】

  • 化学A

    Keio University

    2017.04
    -
    2018.03
    , 

    Spring Semester, Lecture, 2h

  • 物理化学第3

    Keio University

    2017.04
    -
    2018.03
    , 

    Autumn Semester, Lecture

  • 量子化学基礎/生物量子化学

    Keio University

    2017.04
    -
    2018.03
    , 

    Autumn Semester, Lecture

  • 化学実験第1

    Keio University

    2017.04
    -
    2018.03
    , 

    Spring Semester

  • 物理化学第1

    Keio University

    2017.04
    -
    2018.03
    , 

    Spring Semester, Lecture

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Social Activities 【 Display / hide 】

  • 講演会「CHやOH基の振動吸収強度を通して見る分子の電子密度変化」

    新化学技術推進協会　先端化学・材料技術部会, コンピュータケミストリ分科会 講演会 (公益社団法人新化学技術推進協会 A,B会議室 東京都千代田区三番町２ 三番町ＫＳビル　２Ｆ)

    , 
    2019.03

    　View Summary

    RXH(X=C,O)分子のXH伸縮振動には、量子数変化が の基音吸収強度は置換基Rの電子求引性に強く依存するが， の倍音強度はRにほとんど依存しない性質がある。またRXH分子が水素結合を形成すると、多くの場合、XH伸縮振動の基音強度は著しく増大するが、逆に倍音強度は減少する。本講演では振動遷移の遷移モーメントを図的に解釈することで、上記現象が、分子振動の非調和性とその双極子モーメント関数の非線形が共演した結果であること、さらにその分子論的な理解には、概念的DFT法における線形応答理論が有用であることを説明した。

  • 鎌倉学園高校見学会、 模擬講義「物質の色の話」

    慶應義塾大学理工学部広報委員会・キャンパスキャンペーン委員会,  (慶應義塾大学理工学部矢上キャンパス)

    , 
    2015.06

  • 講演会「重原子分子の光吸収過程、光分解過程の理論計算」

    新化学技術推進協会　先端化学・材料技術部会, コンピュータケミストリ分科会 講演会 (公益社団法人新化学技術推進協会 B会議室 東京都千代田区三番町２ 三番町ＫＳビル　２Ｆ)

    , 
    2012.10

    　View Summary

    量子計算技術の長足の進歩によって、簡単な分子の電子基底状態について実験で得られる多くの情報は、理論化学的な手法により定量的に議論できる時代になっている。しかし電子励起状態についてはどうだろう。特に重原子系の光吸収や光分解反応などでは、電子状態は開殻系になり、電子状態は複雑で、原子の運動も非断熱相互作用が顕著になるため、それほど楽観的ではない。
    この講演では、最近我々の研究室で行っている、簡単な分子の光分解反応生成物の分岐比に見られる量子干渉効果、希土類化物のf-f遷移強度、ポリヨウ素の電子励起状態の特性などに研究結果について説明した。

  • Invited lecturer at Institute of Atomic and Molecular Sciences, Academic Sinica, taipei, Taiwan

    Institute of Atomic and Molecular Sciences, Academic Sinica, taipei, Taiwan,  (Institute of Atomic and Molecular Sciences, Academic Sinica, Taipei, Taiwan)

    , 
    2010.11

  • セミナー「理論化学による簡単な分子の光吸収、光分解、光イオン化過程の研究」

    大阪大学基礎工学研究科物質創成, 大阪大学基礎工学研究科物質創成セミナー (大阪大学基礎工学研究科)

    , 
    2008.01

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Media Coverage 【 Display / hide 】

  • 水はなぜ透明？

    NHK, チコちゃんに叱られる, 2019.10

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Academic Activities 【 Display / hide 】

  • QCDB

    量子化学データベース研究会, 

    1992.02
    -
    2004.03

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Memberships in Academic Societies 【 Display / hide 】

  • 原子衝突学会, 

    2012.04
    -
    Present

  • The Society of Iodine Science, 

    2007.07
    -
    Present

  • 分子科学会, 

    2006.11
    -
    Present

  • 理論化学研究会, 

    2002.04
    -
    Present

  • The Chemical Society of Japan, 

    1990.04
    -
    Present
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Committee Experiences 【 Display / hide 】

  • 2020.01
    -
    2021.09

    将来構想委員会, 理論化学会

  • 2016.04
    -
    2020.03

    文部科学省「エネルギーの高効率な創出、変換、貯蔵、利用の新規基盤技術の開発」諮問委員, 文部科学省

  • 2010.09
    -
    2014.08

    運営委員, 分子科学会

  • 2002.02
    -
    2009.05

    理論化学討論会運営委員（第２次世話人）, 理論化学研究会

    　View Remarks

    第11回理論化学討論会　担当世話人2008.05.22-24

  • 2001.04
    -
    2003.03

    日本化学会欧文誌編集委員, 日本化学会

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