Details of the Researcher

PHOTO

Yusuke Ootani
Section
Institute for Materials Research
Job title
Associate Professor
Degree

  • Ph. D (Hokkaido University)

Researcher ID
E-1288-2016

Research History 6

  • 2021/04 - Present
    Institute for Materials Research, Tohoku University　Associate professor

  • 2017/10 - 2021/03
    Institute for Materials Research, Tohoku University　Assistant Professor

  • 2016/01 - 2017/09
    Institute for Materials Research, Tohoku University　pecially Appointed Assistant Professor

  • 2013/04 - 2015/12
    National Institute for Materials Science　NIMS Postdoctoral fellow

  • 2011/06 - 2013/03
    RIKEN Advanced Institute for Computational Science　Postdoctoral Researcher

  • 2011/04 - 2011/05
    Faculty of Science, Hokkaido University　Research Assistant

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Education 3

  • Department of Chemistry, Graduate School of Science, Hokkaido University

    2008/04 - 2011/03

  • Graduate School of Engineering, Kitami Institute of Technology

    2006/04 - 2008/03

  • Kitami Institute of Technology

    2002/04 - 2006/03

Committee Memberships 2

  • 分子シミュレーション学会　会誌編集委員

    2021/01 - 2023/12

  • 日本トライボロジー学会　INTERNATIONAL TRIBOLOGY CONFERENCE実行委員

    2019/05 - 2019/09

Professional Memberships 3

  • JAPANESE SOCIETY OF TRIBOLOGISTS

  • Japan Society of Theoretical Chemistry

  • JAPAN SOCIETY FOR MOLECULAR SCIENCE

Research Interests 6

  • Surface science

  • Mechanochemistry

  • Tribology

  • Electronic excited state dynamics

  • Molecular dynamics simulation

  • Quantum chemistry

Research Areas 2

  • Informatics / Computational science / Quantum chemistry, Molecular dynamics simulation

  • Nanotechnology/Materials / Basic physical chemistry /

Papers 58

  1. Orientation-Dependent Reinforcing Mechanisms of SiC/Carbon Nanotube Composites: A Reactive Molecular Dynamics Simulation Study Peer-reviewed

    Yixin Su, Qian Chen, Shandan Bai, Keiichi Shirasu, Go Yamamoto, Toshiyuki Hashida, Yusuke Ootani, Nobuki Ozawa, Yang Wang, Momoji Kubo

    Langmuir　2025/12/16

    Publisher: American Chemical Society (ACS)

    DOI： 10.1021/acs.langmuir.5c05885 　

    ISSN： 0743-7463

    eISSN： 1520-5827

  2. Effect of aggregate structures of carbon supports on electrode reaction activity in cathode catalyst layers of polymer electrolyte fuel cells: reactive molecular dynamics simulation Peer-reviewed

    Kaito Mori, Tetsuya Nakamura, Shogo Fukushima, Yixin Su, Yusuke Ootani, Nobuki Ozawa, Momoji Kubo

    Chemistry Letters　54　(9)　2025/08/28

    Publisher: Oxford University Press (OUP)

    DOI： 10.1093/chemle/upaf164 　

    ISSN： 0366-7022

    eISSN： 1348-0715

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    Abstract For the high-active catalyst layer in polymer electrolyte fuel cells, we investigated the effect of the location of Pt nanoparticles (exterior or interior on the carbon supports) and the size of the interior pores on the Nafion coverage by using molecular dynamics simulations. We proposed that the large pores of the aggregate carbon supports give both higher proton conductivity and higher oxygen diffusivity, resulting in higher oxygen reduction reaction activity, because of the generation of the non-flexible Nafion cross-linked structure in the large pores.

  3. Continuous formation and removal mechanism of tribolayer on silicon carbide under water lubricated conditions: A ReaxFF reactive molecular dynamics study Peer-reviewed

    Masayuki Kawaura, Yusuke Ootani, Shogo Fukushima, Yixin Su, Nobuki Ozawa, Koshi Adachi, Momoji Kubo

    Tribology International　206　110579-110579　2025/06

    Publisher: Elsevier BV

    DOI： 10.1016/j.triboint.2025.110579 　

    ISSN： 0301-679X

  4. Molecular Dynamics Simulation Study of Organically Modified Nanoparticle Dispersibility in Nonpolar Organic Solvents Peer-reviewed

    Yusuke Ootani, Ryosuke Taniai, Kota Jojima, Miho Nakamura, Shogo Fukushima, Nobuki Ozawa, Momoji Kubo

    ACS Applied Nano Materials　8　(23)　12353-12360　2025/05/29

    Publisher: American Chemical Society (ACS)

    DOI： 10.1021/acsanm.5c02288 　

    ISSN： 2574-0970

    eISSN： 2574-0970

  5. A generalized friction law depicting the thermal effects at chemical bonding interface Peer-reviewed

    Yang Wang, Yexin Li, Xiao Huang, Jingxiang Xu, Yusuke Ootani, Nobuki Ozawa, Koshi Adachi, Linmao Qian, Wen Wang, Momoji Kubo

    Friction　2025/04

    Publisher: Tsinghua University Press

    DOI： 10.26599/frict.2025.9441031 　

    ISSN： 2223-7690

    eISSN： 2223-7704

  6. Reactive molecular dynamics simulation study of wear mechanism of SiO2 and TiO2 passive films on MoSiBTiC alloy in high-temperature humid environment Peer-reviewed

    Keaki Watanabe, Mizuho Yokoi, Masayuki Kawaura, Shogo Fukushima, Yixin Su, Yusuke Ootani, Nobuki Ozawa, Momoji Kubo

    Chemistry Letters　54　upaf049　2025/03

    DOI： 10.1093/chemle/upaf049 　

  7. Development of Coarse-Grained Molecular Dynamics Simulation Model to Elucidate the Wear Behavior of Concentrated Polymer Brushs Peer-reviewed

    Yukihi Hara, Yusuke Ootani, Shuichi Uehara, Arisa Chiba, Shogo Fukushima, Nobuki Ozawa, Momoji Kubo

    Journal of Computer Chemistry, Japan -International Edition　2025

  8. Environment-dependent tribochemical reaction and wear mechanisms of Diamond-like carbon: A reactive molecular dynamics study Peer-reviewed

    Jing Zhang, Yang Wang, Qian Chen, Yixin Su, Shandan Bai, Yusuke Ootani, Nobuki Ozawa, Koshi Adachi, Momoji Kubo

    Carbon　231　119713-119713　2025/01

    Publisher: Elsevier BV

    DOI： 10.1016/j.carbon.2024.119713 　

    ISSN： 0008-6223

  9. Understanding crack growth within the γ′ Fe4N layer in a nitrided low carbon steel during monotonic and cyclic tensile testing Peer-reviewed

    Rama Srinivas Varanasi, Motomichi Koyama, Mizuho Yokoi, Yusuke Ootani, Momoji Kubo, Kento Tanahara, Osamu Umezawa

    Journal of Materials Science　59　(31)　14639-14652　2024/07/28

    Publisher: Springer Science and Business Media LLC

    DOI： 10.1007/s10853-024-10014-x 　

    ISSN： 0022-2461

    eISSN： 1573-4803

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    Abstract Nitriding is a cost-effective method to realize simultaneous improvements in tensile and fatigue properties and resistance to abrasion and corrosion. Previous studies reported that nitriding pure Fe enhances tensile strength by ~ 70% and fatigue limit by ~ 200%. It is due to the increase in surface hardness caused by the formation of γ′(Fe4N) and ε(Fe2-3N) nitrogen-containing intermetallic compound phases. However, the intermetallic compound layer is prone to brittle-like cracking. To better design nitrided steels, it is crucial to identify the crack growth mechanisms via analysis of the microstructural crack growth paths within the ~ 4–6 µm thick nitride layer. In the current work, we statistically evaluate the crack propagation behavior in the γ′ Fe4N layer during monotonic and cyclic tensile deformation in nitrided low-carbon steel (0.1 wt% C). Since nitriding typically results in the formation of columnar grains, the effect of morphology needs to be clarified. To this end, the steel was shot-peened and subsequently nitrided to promote equiaxed nitride grains morphology (~ 16% increase). Crack growth paths were comparatively evaluated for multiple cracks, and no significant effect of nitride morphology was observed. {100}γ′ is the predominant transgranular crack path in the monotonic tensile tested specimen, followed by {111}γ′. It is despite the elastic modulus of {111}γ′ < {100}γ′. This contrary behavior is explained by {100}γ′ plane having the lowest surface energy (density functional theory calculations). In the cyclic tensile loaded specimen, experiments revealed that transgranular cracking along {100}γ′ (cracking via symmetric dislocation emission) or {111}γ′ (slip plane cracking) is equally likely. Graphical abstract

  10. Neural network molecular dynamics simulation on friction-induced chemical reactions of Si3N4 in water and ethylene glycol environments Peer-reviewed

    Ryutaro Kudo, Yusuke Ootani, Shogo Fukushima, Nobuki Ozawa, Momoji Kubo

    Chemistry Letters　53　(7)　2024/07/02

    Publisher: Oxford University Press (OUP)

    DOI： 10.1093/chemle/upae114 　

    ISSN： 0366-7022

    eISSN： 1348-0715

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    Abstract Silicon nitride (Si3N4) exhibits low friction in aqueous environments due to a tribolayer that is formed through tribochemical reactions. However, the low friction state is not maintained in high contact pressure conditions, where surface-surface contact is dominant at the sliding interface, i.e. the load carrying capacity is low. Recently, it was reported that an ethylene glycol (EG) additive improves the load carrying capacity of Si3N4 in aqueous environments, though their mechanism is still in debate. In this study, we performed friction simulations to analyze the tribochemical reactions of water and an EG additive using a neural network molecular dynamics method which enables large-scale simulation with high accuracy comparable with ab initio molecular dynamics calculations. We found that tribochemical reactions of water produce SiO2 particles. On the other hand, tribochemical reactions of EG produce compounds which consist of carbon, nitrogen, and hydrogen atoms on the Si3N4 surface and the Si3N4 surface is covered by the compounds. Based on this finding, we propose that the compounds covering the Si3N4 surface can improve its load carrying capacity.

  11. Reticular Imine‐linked Coordination Polymers Based on Paddlewheel Diruthenium/Dirhodium Nodes: Synthesis and Metal‐site Dependent Photocatalytic Reduction of CO2 Peer-reviewed

    Chisa Itoh, Masaki Kitada, Mio Kondo, Shigeyuki Masaoka, Haruka Yoshino, Wataru Kosaka, Yusuke Ootani, Junko Matsuda, Momoji Kubo, Toyohiko J. Konno, Hitoshi Miyasaka

    ChemSusChem　2024/06/18

    Publisher: Wiley

    DOI： 10.1002/cssc.202400885 　

    ISSN： 1864-5631

    eISSN： 1864-564X

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    The paddlewheel‐type dimetal core ([M2]) is a ubiquitous motif in the nodes in coordination polymers (CPs) and metal–organic frameworks (MOFs). However, their preparation has relied on ligand‐substitution‐labile metal ions owing to challenges associated with crystallization. Consequently, examples featuring ligand‐substitution‐inert metal ions, such as Ru or Rh, are scarce. This study presents the synthesis of novel reticular imine‐linked CPs incorporating the paddlewheel‐type diruthenium(II, II) ([Ru2II,II]; 1‐Ru) or dirhodium(II, II) ([Rh2II,II]; 1‐Rh) subunits. The synthetic approach involved a Schiff base dehydration condensation reaction between p‐formylbenzoate‐bridged [Ru2II,II] or [Rh2II,II] precursors (i.e., CHO–Ru and CHO–Rh, respectively) and 2,5‐dimethyl‐1,4‐phenylenediamine in a 1:2 ratio. The catalytic activities of 1‐Ru and 1‐Rh for the photochemical reduction of CO2 in a heterogeneous system depended on the metal site. The 1‐Rusystem exhibited exceptional selectivity, generating 3.0 ´ 104 mmol g‐1 of CO after 24 h of irradiation, whereas the 1‐Rhsystem generated a lower amount of CO (3.2 ´ 103 mmol g‐1). The catalytic activity of 1‐Ru ranked with that of all relevant catalytic systems. This study paves the way for the exploration of [Ru2II,II]‐ or [Rh2II,II]‐based polymers with open metal site‐dependent functional properties.

  12. Coarse-grained molecular dynamics simulation of the effect of cross-linking on the wear mechanism of polymer brush Peer-reviewed

    Zhongmin Liu, Yusuke Ootani, Shuichi Uehara, Jing Zhang, Qian Chen, Yang Wang, Nobuki Ozawa, Momoji Kubo

    Chemistry Letters　53　(3)　2024/03/01

    Publisher: Oxford University Press (OUP)

    DOI： 10.1093/chemle/upae035 　

    ISSN： 0366-7022

    eISSN： 1348-0715

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    Abstract The effects of a cross-linking layer on the wear resistance of polymer brush were investigated by using molecular dynamics-based sliding simulations. We found that a cross-linking layer improved wear resistance. The cross-linking layer suppressed the interpenetration of polymer chains on the counter surface and thus lowered the frictional force and wear. The degrees of interpenetration decreased as the cross-linking layer closed to the tip of the chain. A cross-linking layer in the tip of the polymer chains was thus found to improve wear resistance most effectively.

  13. Reactive Molecular Dynamics Simulation Study on Atomic-Scale Adhesive Wear Mechanisms of Single Crystalline Body-Centered Cubic Iron Peer-reviewed

    Yusuke Ootani, Masaki Tsuchiko, Masayuki Kawaura, Mizuho Yokoi, Qian Chen, Yuta Asano, Nobuki Ozawa, Momoji Kubo

    Tribology Letters　72　(2)　2024/03/01

    Publisher: Springer Science and Business Media LLC

    DOI： 10.1007/s11249-024-01834-8 　

    ISSN： 1023-8883

    eISSN： 1573-2711

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    Abstract The adhesive wear of steel is a crucial issue in many industrial fields because it can lead to serious machine failure. However, the adhesive wear mechanism is still under debate owing to its complexity. Therefore, in this work, we performed reactive molecular dynamics-based sliding simulations of single crystalline body-centered cubic iron and investigated the fundamental atomic-scale adhesive wear mechanism for improving the wear resistance of steel. The effects of surface orientation, sliding direction, and humid atmosphere on the adhesive wear property were analyzed. In the sliding simulation, we observed two adhesive wear types. One is the wear accompanying surface deformation, in which the surface asperities gradually deform by slip and adhere severely. The other is the wear accompanying surface fracture with crack generation. The former can lead to seizures, whereas the latter can lead to wear debris formation. We propose that the rubbing surface orientation and sliding direction alter the atomic-scale adhesive wear type. Wear with surface deformation occurred when the deformation by slip was favorable, whereas wear with surface fracture occurred when slip was not favorable. Understanding the adhesive wear mechanism of iron in humid atmospheres is also important in many industrial fields. When water molecules were present at the sliding interface, both types of adhesive wear were suppressed. At the sliding interface, Fe–OH and Fe–O–Fe groups were formed on the scars through the tribochemical reaction with water. These groups passivated the nascent Fe surfaces and suppressed adhesion to the counter surface, thereby reducing adhesive wear. Therefore, we conclude that the surface orientation and sliding direction determine the atomic-scale adhesive wear type, whereas a humid atmosphere affects the wear amount at the atomic scale.

  14. Mechanisms of chemical-reaction-induced tensile deformation of an Fe/Ni/Cr alloy revealed by reactive atomistic simulations Peer-reviewed

    Yang Wang, Haoyu Zhao, Chang Liu, Yusuke Ootani, Nobuki Ozawa, Momoji Kubo

    RSC Advances　13　(10)　6630-6636　2023

    Publisher: Royal Society of Chemistry (RSC)

    DOI： 10.1039/d2ra07039a 　

    eISSN： 2046-2069

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    Chemical-reaction-induced deformation mechanism change from FCC-to-HCP to FCC-to-BCC phase transition of high entropy alloy.

  15. Density-Functional Tight-Binding Molecular Dynamics Simulation of the Bending Mechanism of Molecular Crystals Peer-reviewed

    Yusuke Ootani, Momoji Kubo

    The Journal of Physical Chemistry C　126　(25)　10554-10565　2022/06/30

    Publisher: American Chemical Society (ACS)

    DOI： 10.1021/acs.jpcc.2c02504 　

    ISSN： 1932-7447

    eISSN： 1932-7455

  16. Chemical-Reaction-Induced deformation of Body-Centered cubic iron in supercritical water leading to high risk of cleavage Fracture: A reactive Molecular dynamics study Peer-reviewed

    Qian Chen, Jingxiang Xu, Yixin Su, Shuichi Uehara, Shandan Bai, Yang Wang, Yusuke Ootani, Nobuki Ozawa, Momoji Kubo

    Computational Materials Science　208　111354-111354　2022/06

    Publisher: Elsevier BV

    DOI： 10.1016/j.commatsci.2022.111354 　

    ISSN： 0927-0256

  17. Three Tribolayers Self-Generated from SiC Individually Work for Reducing Friction in Different Contact Pressures Peer-reviewed

    Yusuke Ootani, Jingxiang Xu, Fumiya Nakamura, Masayuki Kawaura, Shuichi Uehara, Koki Kanda, Yang Wang, Nobuki Ozawa, Koshi Adachi, Momoji Kubo

    The Journal of Physical Chemistry C　126　(5)　2728-2736　2022/02/10

    Publisher: American Chemical Society (ACS)

    DOI： 10.1021/acs.jpcc.1c07668 　

    ISSN： 1932-7447

    eISSN： 1932-7455

  18. Molecular-Level Elucidation of a Fracture Process in Slide-Ring Gels via Coarse-Grained Molecular Dynamics Simulations Peer-reviewed

    Shuichi Uehara, Yang Wang, Yusuke Ootani, Nobuki Ozawa, Momoji Kubo

    Macromolecules　55　(6)　1946-1956　2022/02/09

    Publisher: American Chemical Society (ACS)

    DOI： 10.1021/acs.macromol.1c01981 　

    ISSN： 0024-9297

    eISSN： 1520-5835

  19. Effect of Water and Oxygen at Sliding Interface on Friction and Wear of Diamond-like Carbon/Steel: Reactive Molecular Dynamics Simulations Peer-reviewed

    Mizuho YOKOI, Masayuki KAWAURA, Yuta ASANO, Qian CHEN, Yusuke OOTANI, Nobuki OZAWA, Momoji KUBO

    Journal of Computer Chemistry, Japan -International Edition　8　n/a-n/a　2022

    Publisher: Society of Computer Chemistry Japan

    DOI： 10.2477/jccjie.2022-0009 　

    eISSN： 2189-048X

  20. Atom-by-Atom and Sheet-by-Sheet Chemical Mechanical Polishing of Diamond Assisted by OH Radicals: A Tight-Binding Quantum Chemical Molecular Dynamics Simulation Study Peer-reviewed

    Kentaro Kawaguchi, Yang Wang, Jingxiang Xu, Yusuke Ootani, Yuji Higuchi, Nobuki Ozawa, Momoji Kubo

    ACS Applied Materials & Interfaces　13　(34)　41231-41237　2021/09/01

    Publisher: American Chemical Society (ACS)

    DOI： 10.1021/acsami.1c09468 　

    ISSN： 1944-8244

    eISSN： 1944-8252

  21. Heterogeneous yielding mechanisms of body centered cubic iron for high resistance to chemical reaction-induced deterioration in supercritical water environments: A reactive molecular dynamics study Peer-reviewed

    Qian Chen, Jing Zhang, Zhongmin Liu, Yang Wang, Yusuke Ootani, Jingxiang Xu, Nobuki Ozawa, Momoji Kubo

    Scripta Materialia　202　113997-113997　2021/09

    Publisher: Elsevier BV

    DOI： 10.1016/j.scriptamat.2021.113997 　

    ISSN： 1359-6462

  22. Selective Wear Behaviors of a Water-Lubricating SiC Surface under Rotating-Contact Conditions Revealed by Large-Scale Reactive Molecular Dynamics Simulations Peer-reviewed

    Yang Wang, Keita Yukinori, Ryo Koike, Yusuke Ootani, Koshi Adachi, Momoji Kubo

    The Journal of Physical Chemistry C　125　(27)　14957-14964　2021/07/15

    Publisher: American Chemical Society (ACS)

    DOI： 10.1021/acs.jpcc.1c02765 　

    ISSN： 1932-7447

    eISSN： 1932-7455

  23. Role of OH Termination in Mitigating Friction of Diamond-like Carbon under High Load: A Joint Simulation and Experimental Study Peer-reviewed

    Yang Wang, Kentaro Hayashi, Yusuke Ootani, Shandan Bai, Tomomi Shimazaki, Yuji Higuchi, Nobuki Ozawa, Koshi Adachi, Maria-Isabel De Barros Bouchet, Jean Michel Martin, Momoji Kubo

    Langmuir　37　(20)　6292-6300　2021/05/25

    DOI： 10.1021/acs.langmuir.1c00727 　

    ISSN： 0743-7463

    eISSN： 1520-5827

  24. Effect of Pore Size of Carbon Support on Electrode Reaction Activity of Catalyst Layer in Polymer Electrolyte Fuel Cell: Reactive Molecular Dynamics Simulations Peer-reviewed

    Tetsuya NAKAMURA, Riku OTSUKI, Shuichi UEHARA, Yuta ASANO, Qian CHEN, Yusuke OOTANI, Nobuki OZAWA, Momoji KUBO

    Journal of Computer Chemistry, Japan　20　(4)　150-154　2021

    Publisher: Society of Computer Chemistry Japan

    DOI： 10.2477/jccj.2022-0008 　

    ISSN： 1347-1767

    eISSN： 1347-3824

  25. Cooperative roles of chemical reactions and mechanical friction in chemical mechanical polishing of gallium nitride assisted by OH radicals: tight-binding quantum chemical molecular dynamics simulations Peer-reviewed

    Kentaro Kawaguchi, Yang Wang, Jingxiang Xu, Yusuke Ootani, Yuji Higuchi, Nobuki Ozawa, Momoji Kubo

    Physical Chemistry Chemical Physics　23　(7)　4075-4084　2021

    Publisher: Royal Society of Chemistry (RSC)

    DOI： 10.1039/d0cp05826b 　

    ISSN： 1463-9076

    eISSN： 1463-9084

  26. Non‐Empirical Law for Nanoscale Atom‐by‐Atom Wear Peer-reviewed

    Yang Wang, Jingxiang Xu, Yusuke Ootani, Nobuki Ozawa, Koshi Adachi, Momoji Kubo

    Advanced Science　8　(2)　2002827-2002827　2020/12/07

    DOI： 10.1002/advs.202002827 　

    ISSN： 2198-3844

    eISSN： 2198-3844

  27. Coarse-grained Molecular Dynamics Simulation of the Wear Mechanism of Cyclic Polymer Brushes Peer-reviewed

    Zhongmin Liu, Yusuke Ootani, Shuichi Uehara, Jingxiang Xu, Yang Wang, Narumasa Miyazaki, Yuji Higuchi, Nobuki Ozawa, Momoji Kubo

    Chemistry Letters　49　(10)　1185-1188　2020/10/05

    Publisher: The Chemical Society of Japan

    DOI： 10.1246/cl.200323 　

    ISSN： 0366-7022

    eISSN： 1348-0715

  28. First-Principles Molecular Dynamics Study of Silicon-Based Ceramics: Different Tribochemical Reaction Mechanisms during the Running-in Period of Silicon Nitride and Silicon Carbide Peer-reviewed

    Yusuke Ootani, Jingxiang Xu, Koshi Adachi, Momoji Kubo

    The Journal of Physical Chemistry C　124　(37)　20079-20089　2020/09/17

    Publisher: American Chemical Society (ACS)

    DOI： 10.1021/acs.jpcc.0c04613 　

    ISSN： 1932-7447

    eISSN： 1932-7455

  29. Reactive Molecular Dynamics Simulations of Wear and Tribochemical Reactions of Diamond like Carbon Interfaces with Nanoscale Asperities under H2 Gas: Implications for Solid Lubricant Coatings Peer-reviewed

    Yang Wang, Yixin Su, Jing Zhang, Qian Chen, Jingxiang Xu, Shandan Bai, Yusuke Ootani, Nobuki Ozawa, Maria-Isabel De Barros Bouchet, Jean Michel Martin, Koshi Adachi, Momoji Kubo

    ACS Applied Nano Materials　3　(7)　7297-7304　2020/07/24

    Publisher: American Chemical Society (ACS)

    DOI： 10.1021/acsanm.0c01775 　

    ISSN： 2574-0970

    eISSN： 2574-0970

  30. Trajectory on‐the‐fly molecular dynamics approach to tunneling splitting in the electronic excited state: A case of tropolone Peer-reviewed

    Yusuke Ootani, Aya Satoh, Yu Harabuchi, Tetsuya Taketsugu

    Journal of Computational Chemistry　41　(16)　1549-1556　2020/06/15

    DOI： 10.1002/jcc.26199 　

    ISSN： 0192-8651

    eISSN： 1096-987X

  31. Self-Formed Double Tribolayers Play Collaborative Roles in Achieving Superlow Friction in an Aqueous Environment Peer-reviewed

    Yusuke Ootani, Jingxiang Xu, Naoki Takahashi, Kenta Akagami, Satoshi Sakaki, Yang Wang, Nobuki Ozawa, Takahiro Hatano, Koshi Adachi, Momoji Kubo

    The Journal of Physical Chemistry C　124　(15)　8295-8303　2020/04/16

    DOI： 10.1021/acs.jpcc.0c02068 　

    ISSN： 1932-7447

    eISSN： 1932-7455

  32. Reactive Molecular Dynamics Simulation on Friction-induced Chemical Reactions of SiC in Water Environments Peer-reviewed

    Masayuki KAWAURA, Yang WANG, Yusuke OOTANI, Nobuki OZAWA, Momoji KUBO

    Journal of Computer Chemistry, Japan　19　(4)　139-141　2020

    Publisher: Society of Computer Chemistry Japan

    DOI： 10.2477/jccj.2021-0010 　

    ISSN： 1347-1767

    eISSN： 1347-3824

  33. Proposal of a new formation mechanism for hydrogenated diamond-like carbon transfer films: Hydrocarbon-emission-induced transfer Peer-reviewed

    Yang Wang, Jingxiang Xu, Yusuke Ootani, Nobuki Ozawa, Koshi Adachi, Momoji Kubo

    CARBON　154　7-12　2019/12

    DOI： 10.1016/j.carbon.2019.07.090 　

    ISSN： 0008-6223

    eISSN： 1873-3891

  34. Triboemission of hydrocarbon molecules from diamond-like carbon friction interface induces atomic-scale wear Peer-reviewed

    Yang Wang, Naohiro Yamada, Jingxiang Xu, Jing Zhang, Qian Chen, Yusuke Ootani, Yuji Higuchi, Nobuki Ozawa, Maria-Isabel De Barros Bouchet, Jean Michel Martin, Shigeyuki Mori, Koshi Adachi, Momoji Kubo

    SCIENCE ADVANCES　5　(11)　2019/11

    DOI： 10.1126/sciadv.aax9301 　

    ISSN： 2375-2548

  35. Prediction of Macroscopic Properties of Diamond-like Carbon from Atomic-Scale Structure Peer-reviewed

    Jingxiang Xu, Yang Wang, Yuxin Cen, Bowen Xing, Xingwei Zheng, Yusuke Ootani, Momoji Kubo

    JOURNAL OF PHYSICAL CHEMISTRY C　123　(40)　24609-24614　2019/10

    DOI： 10.1021/acs.jpcc.9b07320 　

    ISSN： 1932-7447

    eISSN： 1932-7455

  36. Influence of Surface Orientation on Electrochemical Properties of Boron-Doped Diamond Peer-reviewed

    Ivandini Tribidasari A, Watanabe Takeshi, Matsui Takahiro, Ootani Yusuke, Iizuka Shota, Toyoshima Ryo, Kodama Hideki, Kondoh Hiroshi, Tateyama Yoshitaka, Einaga Yasuaki

    JOURNAL OF PHYSICAL CHEMISTRY C　123　(9)　5336-5344　2019/03/07

    DOI： 10.1021/acs.jpcc.8b10406 　

    ISSN： 1932-7447

    eISSN： 1932-7455

  37. Development of Coarse-grained Molecular Dynamics Friction Simulator and Its Application to Bottlebrush Polymer Peer-reviewed

    Shuichi Uehara, Zhongmin Liu, Narumasa Miyazaki, Yusuke Ootani, Nobuki Ozawa, Momoji Kubo

    JOURNAL OF COMPUTER CHEMISTRY-JAPAN　18　(2)　105-107　2019

    DOI： 10.2477/jccj.2019-0005 　

    ISSN： 1347-1767

    eISSN： 1347-3824

  38. A Molecular Dynamics Study on Alumina/Carbon Nanotube Composite: How Does Annealing Affect Mechanical Properties? Peer-reviewed

    Yixin SU, Jing ZHANG, Qian CHEN, Yang WANG, Narumasa MIYAZAKI, Yusuke OOTANI, Nobuki OZAWA, Momoji KUBO

    Journal of Computer Chemistry, Japan　18　(5)　259-262　2019

    Publisher: Society of Computer Chemistry Japan

    DOI： 10.2477/jccj.2020-0001 　

    ISSN： 1347-1767

    eISSN： 1347-3824

  39. Graphitization Dynamics of DLC under Water Lubrication Revealed by Molecular Dynamics Simulation Peer-reviewed

    Jing Zhang, Yang Wang, Qian Chen, Yixin Su, Jingxiang Xu, Yusuke Ootani, Nobuki Ozawa, Koshi Adachi, Momoji Kubo

    JOURNAL OF COMPUTER CHEMISTRY-JAPAN　18　(2)　103-104　2019

    DOI： 10.2477/jccj.2019-0001 　

    ISSN： 1347-1767

    eISSN： 1347-3824

  40. Molecular Interactions between Pentacene and Imidazolium Ionic Liquids: A Molecular Dynamics Study Peer-reviewed

    Ida Bagus Hendra Prastiawan, Jingxiang Xu, Yusuke Ootani, Yuji Higuchi, Nobuki Ozawa, Shingo Maruyama, Yuji Matsumoto, Momoji Kubo

    Chemistry Letters　47　(9)　1154-1157　2018/09/05

    DOI： 10.1246/cl.180450 　

    ISSN： 0366-7022

    eISSN： 1348-0715

  41. Tribochemical reactions and graphitization of diamond-like carbon against alumina give volcano-type temperature dependence of friction coefficients: A tight-binding quantum chemical molecular dynamics simulation Peer-reviewed

    Yang Wang, Jingxiang Xu, Jing Zhang, Qian Chen, Yusuke Ootani, Yuji Higuchi, Nobuki Ozawa, Jean Michel Martin, Koshi Adachi, Momoji Kubo

    Carbon　133　350-357　2018/07/01

    Publisher: Elsevier Ltd

    DOI： 10.1016/j.carbon.2018.03.034 　

    ISSN： 0008-6223

  42. Contrasting Roles of Water at Sliding Interfaces between Silicon-Based Materials: First-Principles Molecular Dynamics Sliding Simulations Peer-reviewed

    Yusuke Ootani, Jingxiang Xu, Takahiro Hatano, Momoji Kubo

    Journal of Physical Chemistry C　122　(19)　10459-10467　2018/05/17

    DOI： 10.1021/acs.jpcc.8b01953 　

    ISSN： 1932-7455 1932-7447

  43. Effect of fluorination on friction forces between concentrated polymer brushes in the dry state: All-atom molecular dynamics simulation study Peer-reviewed

    Shuichi Uehara, Zhongmin Liu, Jingxiang Xu, Yusuke Ootani, Nobuki Ozawa, Momoji Kubo

    Chemistry Letters　47　(6)　784-786　2018

    DOI： 10.1246/cl.180183 　

    ISSN： 1348-0715 0366-7022

  44. Tight-Binding Quantum Chemical Molecular Dynamics Study on the Friction and Wear Processes of Diamond-Like Carbon Coatings: Effect of Tensile Stress Peer-reviewed

    Yang Wang, Jingxiang Xu, Yusuke Ootani, Shandan Bai, Yuji Higuchi, Nobuki Ozawa, Koshi Adachi, Jean Michel Martin, Momoji Kubo

    ACS APPLIED MATERIALS & INTERFACES　9　(39)　34396-34404　2017/10

    DOI： 10.1021/acsami.7b07551 　

    ISSN： 1944-8244

  45. Parameterization of Reactive Force Field for Iron-Water System Peer-reviewed

    Chen Qian, Xu Jingxiang, Ootani Yusuke, Ozawa Nobuki, Kubo Momoji

    JOURNAL OF COMPUTER CHEMISTRY-JAPAN　16　(4)　110-111　2017/10

    DOI： 10.2477/jccj.2017-0041 　

    ISSN： 1347-1767

  46. Effect of Polarity of a Substrate on ZnO Crystal Growth Process by Molecular Dynamics Simulation Peer-reviewed

    KAWAGISHI Shunsuke, XU Jingxiang, OOTANI Yusuke, NISHIMATSU Takeshi, HIGUCHI Yuji, OZAWA Nobuki, KUBO Momoji

    Journal of Computer Chemistry, Japan　15　(6)　244-245　2017

    Publisher: 日本コンピュータ化学会

  47. A Study on Electrolytic Corrosion of Boron-Doped Diamond Electrodes when Decomposing Organic Compounds Peer-reviewed

    Takeshi Kashiwada, Takeshi Watanabe, Yusuke Ootani, Yoshitaka Tateyama, Yasuaki Einaga

    ACS APPLIED MATERIALS & INTERFACES　8　(42)　28299-28305　2016/10

    DOI： 10.1021/acsami.5b11638 　

    ISSN： 1944-8244

  48. First-principles study on the cosensitization effects of Ru and squaraine dyes on a TiO2 surface Peer-reviewed

    Yusuke Ootani, Keitaro Sodeyama, Liyuan Han, Yoshitaka Tateyama

    SURFACE SCIENCE　649　66-71　2016/07

    DOI： 10.1016/j.susc.2016.01.025 　

    ISSN： 0039-6028

    eISSN： 1879-2758

  49. Theoretical Investigation of Enantioselectivity of Cage-Like Supramolecular Assembly: The Insights into the Shape Complementarity and Host-Guest Interaction Peer-reviewed

    Yusuke Ootani, Yoshinobu Akinaga, Takahito Nakajima

    JOURNAL OF COMPUTATIONAL CHEMISTRY　36　(7)　459-466　2015/03

    DOI： 10.1002/jcc.23821 　

    ISSN： 0192-8651

    eISSN： 1096-987X

  50. Possibility of NCS Group Anchor for Ru Dye Adsorption to Anatase TiO2(101) Surface: A Density Functional Theory Investigation Peer-reviewed

    Yusuke Ootani, Keitaro Sodeyama, Liyuan Han, Yoshitaka Tateyama

    JOURNAL OF PHYSICAL CHEMISTRY C　119　(1)　234-241　2015/01

    DOI： 10.1021/jp5075434 　

    ISSN： 1932-7447

  51. Acetonitrile Solution Effect on Ru N749 Dye Adsorption and Excitation at TiO2 Anatase Interface Peer-reviewed

    Yoshitaka Tateyama, Masato Sumita, Yusuke Ootani, Koharu Aikawa, Ryota Jono, Liyuan Han, Keitaro Sodeyama

    JOURNAL OF PHYSICAL CHEMISTRY C　118　(30)　16863-16871　2014/07

    DOI： 10.1021/jp5004006 　

    ISSN： 1932-7447

  52. Ab Initio Molecular Dynamics Approach to Tunneling Splitting in Polyatomic Molecules Peer-reviewed

    Yusuke Ootani, Tetsuya Taketsugu

    JOURNAL OF COMPUTATIONAL CHEMISTRY　33　(1)　60-65　2012/01

    DOI： 10.1002/jcc.21943 　

    ISSN： 0192-8651

  53. Ab initio molecular dynamics simulation of photoisomerization in azobenzene in the n pi(*) state Peer-reviewed

    Yusuke Ootani, Kiminori Satoh, Akira Nakayama, Takeshi Noro, Tetsuya Taketsugu

    JOURNAL OF CHEMICAL PHYSICS　131　(19)　194306-1-10　2009/11

    DOI： 10.1063/1.3263918 　

    ISSN： 0021-9606

  54. Decoupling of the Dirac equation correct to the third order for the magnetic perturbation Peer-reviewed

    Y. Ootani, H. Maeda, H. Fukui

    JOURNAL OF CHEMICAL PHYSICS　127　(8)　084117-1-7　2007/08

    DOI： 10.1063/1.2759199 　

    ISSN： 0021-9606

    eISSN： 1089-7690

  55. Relativistic calculation of nuclear magnetic shielding tensor using the regular approximation to the normalized elimination of the small component. II. Consideration of perturbations in the metric operator Peer-reviewed

    H. Maeda, Y. Ootani, H. Fukui

    JOURNAL OF CHEMICAL PHYSICS　126　(17)　174102-1-6　2007/05

    DOI： 10.1063/1.2733650 　

    ISSN： 0021-9606

  56. Relativistic calculation of nuclear magnetic shielding tensor including two-electron spin-orbit interactions Peer-reviewed

    Y. Ootani, H. Yamaguti, H. Maeda, H. Fukui

    JOURNAL OF CHEMICAL PHYSICS　125　(16)　164106-1-4　2006/10

    DOI： 10.1063/1.2361292 　

    ISSN： 0021-9606

    eISSN： 1089-7690

  57. Relativistic calculation of nuclear magnetic shielding using normalized elimination of the small component Peer-reviewed

    K Kudo, H Maeda, T Kawakubo, Y Ootani, M Funaki, H Fukui

    JOURNAL OF CHEMICAL PHYSICS　124　(22)　224106-1-7　2006/06

    DOI： 10.1063/1.2204606 　

    ISSN： 0021-9606

  58. Relativistic calculation of nuclear magnetic shieldings of xenon difluoride Peer-reviewed

    K Kudo, Y Ootani, M Funaki, H Fukui

    JOURNAL OF CHEMICAL PHYSICS　124　(11)　116101-1-2　2006/03

    DOI： 10.1063/1.2173999 　

    ISSN： 0021-9606

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Books and Other Publications 11

  1. 24th International Colloquium Tribology, Industrial and Automotive Lubrication Conference Proceedings 2024

    M. Yokoi, M. Kawaura, S. Fukushima, Y. Asano, Y. Ootani, N. Ozawa, M. Kubo

    2023

  2. フロンティア 第5巻

    大谷優介, 久保百司

    理論化学会　2023

  3. トライボロジスト 第69巻

    樋口祐次, 高桑諒, 大谷優介, 久保百司

    一般社団法人日本トライボロジー学会　2023

  4. トライボロジスト 第68巻

    大谷優介, 久保百司

    一般社団法人日本トライボロジー学会　2023

  5. Diamond Electrodes –Fundamentals and Applications–

    Y. Tateyama, Z. Futera, Y. Ootani, S. Iizuka, L. T. Anh

    Springer　2022/03

    ISBN: 9789811678332

  6. Spectroscopy and Computation of Hydrogen-Bonded Systems

    T. Taketsugu, Y. Ootani

    Wiley-VCH GmbH　2022

    ISBN: 9783527349722

  7. セラミックス 第56巻

    川浦正之, 大谷優介, 久保百司

    日本セラミックス協会　2021

  8. フロンティア 第3巻

    大谷優介, 王楊, 足立幸志, 久保百司

    理論化学会　2021

  9. トライボロジスト 第66巻

    大谷優介, 足立幸志, 久保百司

    一般社団法人日本トライボロジー学会　2021

  10. 高分子材料のトライボロジー制御

    上原周一, 大谷優介, 久保百司

    技術情報協会　2020

  11. 数値解析と表面分析によるトライボロジーの解明と制御

    大谷優介, 久保百司

    株式会社テクノシステム　2018

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Presentations 43

  1. Molecular Dynamics Simulation Study on Deformation Mechanism of Flexible Organic Materials

    Pacifichem2025　2025/12

  2. Investigation of Photoinduced Electronic Excited-State Molecular Dynamics Responsible for Bending of Flexible Organic Materials: Time-dependent Density Functional Tight-binding Molecular Dynamics Simulation

    Pacifichem2025　2025/12

  3. 高分子材料の摩耗・破壊の理解に向けた分子動力学シミュレーション Invited

    大谷優介

    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　2025/08

  4. Molecular Dynamics Simulation Study on Mechanochemical Dynamics in Materials Invited

    Yusuke Ootani

    2025/04

  5. Molecular Dynamics Simulation Study on Microscale Wear Mechanism of Concentrated Polymer Brushes Invited

    Yusuke Ootani

    2025/02

  6. 溶媒中における有機修飾ナノ粒子の分散/凝集メカニズムの粗視化分子動力学シミュレーション解析 Invited

    大谷優介

    第62回 オーロラセミナー　2024/10

  7. ニューラルネットワーク分子動力学法による摩擦誘起の化学反応プロセスの解析: 窒化ケイ素水潤滑システムにおける耐荷重性向上添加剤の化学反応

    大谷優介, 工藤龍太郎, 福島省吾, 尾澤伸樹, 久保百司

    第26回理論化学討論会　2024/05

  8. Atomic-Scale Deformation/Fracture Process of Molecular Crystals: Density-Functional Tight Binding Molecular Dynamics Simulations

    Y. Ootani, M. Kubo

    The 3rd Materials Research Meeting (MRM 2023) / The 24th IUMRS-International Conference in Asia (IUMRS-ICA 2023) Kyoto, December 2023　2023/12

  9. Reactive Molecular Dynamics Simulation Study on Microscopic Corrosive Wear Process of Iron Nitride Invited

    Y. Ootani

    The 3rd Materials Research Meeting (MRM 2023) / The 24th IUMRS-International Conference in Asia (IUMRS-ICA 2023)　2023/12

  10. Frictional Property of Concentrated Polymer Brush Elucidated by Molecular Dynamics Simulation

    Y. Ootani

    Summit of Materials Science 2023 and GIMRT User Meeting 2023　2023/11

  11. Density-Functional Tight Binding Molecular Dynamics Approach for Deformation/Fracture Mechanisms of Molecular Crystals

    Y. Ootani, M. Kubo

    The 5th conference of Theory and Applications of Computational Chemistry　2023/09

  12. Molecular Dynamics Simulation Study on Tribochemical Reaction in Water Lubrication of Silicon Carbide Invited

    Y. Ootani

    9th International Tribology Conference, Fukuoka 2023　2023/09

  13. 超低摩擦を発現する濃厚ポリマーブラシ摩耗プロセスの粗視化分子動力学シミュレーション解析

    大谷優介

    計算科学と情報科学を用いた材料開発の新展開–2023　2023/08

  14. ナノ粒子大量生産プロセスの設計に向けた有機修飾ナノ粒子凝集メカニズムの粗視化分子動力学シミュレーション解析

    大谷優介, 谷合凌輔, 城島浩太, 中村美穂, 久保百司

    第25回理論化学討論会　2023/05

  15. 力学作用によって誘起される化学現象の解明に向けたスーパーコンピュータ分子動力学シミュレーション

    大谷優介

    第143回東北大学金属材料研究所講演会　2022/11

  16. 密度汎関数強束縛分子動力学法による分子結晶の変形/破壊メカニズムの解析

    大谷優介, 久保百司

    第24回理論化学討論会　2022/05

  17. Reactive all-atom molecular dynamics study on fracture process of semi-crystalline polyethylene

    2022/05

  18. 粗視化分子動力学シミュレーションによる有機修飾ナノ粒子の凝集性の解析 Invited

    大谷優介, 谷合凌輔, 久保百司

    化学工学会第52回秋季大会　2021/10

  19. Molecular Dynamics Simulation Study on Mechanochemical Reaction Dynamics at Sliding Interface Invited

    大谷優介

    令和3年度化学系学協会東北大会　2021/10

  20. Molecular Dynamics Study on the Super-low Friction Mechanism of Silicon Carbide in Water Invited

    Yusuke Ootani, Momoji Kubo

    The 24th International Annual Symposium on Computational Science and Engineering　2021/05/28

  21. 鉄の摩擦界面における水のトライボ化学反応が摩擦・摩耗に与える影響: 反応分子動力学シミュレーション解析

    大谷優介, 土子政貴, 王楊, 尾澤伸樹, 久保百司

    トライボロジー会議2021春 2021　2021/05/24

  22. 炭化ケイ素の摩擦界面で起こる潤滑膜自己形成の化学反応ダイナミクス

    大谷優介, 中村文哉, 王楊, 尾澤伸樹, 久保百司

    第23回 理論科学討論会　2021/05/15

  23. シリコン系セラミックスの摩擦界面で自己形成する潤滑膜の分子動力学シミュレーション解析

    大谷優介, 許競翔, 高橋直己, 赤上研太, 足立幸志, 久保百司

    第33回 分子シミュレーション　2019/12

  24. Supercomputer Simulation of Atomic Scale Friction for Design of Sliding Materials

    GIMRT X ISS-"Kibo" Users' Network X AIRC ~International Collaborative Research Platform on Ground and in Orbit~　2019/11

  25. Molecular Dynamics and Friction Experiment Study on Super-Low Friction Mechanism of Silicon-Based Ceramics in Water Lubrication

    Y. Ootani, J. Xu, N. Takahashi, K. Akagami, K. Adachi, M. Kubo

    ITC Sendai 2019　2019/09

  26. Reactive Molecular Dynamics Simulation Study on Tribofilm Formation Process of Silicon Carbide in Water

    Y. Ootani, J. Xu, F. Nakamura, Y. Wang, K. Adachi, M. Kubo

    2019/09

  27. ケイ素系セラミックスが水中で発現する超低摩擦メカニズム：機械におけるなじみ現象の理解に向けた計算と実験の連携

    大谷優介, 許競翔, 高橋直己, 赤上研太, 足立幸志, 久保百司

    第22回理論科学討論会　2019/05

  28. 炭化ケイ素のトライボ膜形成プロセスと低摩擦発現メカニズムの分子動力学シミュレーション解析

    大谷優介, 中村文哉, 王楊, 足立幸志, 久保百司

    トライボロジー会議2019春 東京　2019/05

  29. Molecular Dynamics Simulation Study on the Structure, Role, and Formation Mechanism of Tribofilms of Silicon-Based Materials in Water

    Y. Ootani, J. Xu, N. Takahashi, K. Adachi, M. Kubo

    The 9th International Conference on Multiscale Materials Modeling　2018/10

  30. Molecular Dynamics Simulation Study on Tribolayer Formation of Silicon-Based Ceramics in Water Lubrication System

    Y. Ootani, J. Xu, N. Takahashi, M. Kubo

    SMS2018 SUMMIT of MATERIALS SCIENCE　2018/10

  31. ケイ素セラミックスの摩擦界面で自己形成する潤滑膜の分子動力学計算解析

    大谷優介, 許競翔, 高橋直己, 足立幸志, 久保百司

    第12回分子科学討論会　2018/09

  32. 岩石のミクロな摩擦現象と地震メカニズムに関する連携研究

    大谷優介, 久保百司, 波多野恭弘

    第2回ポスト「京」萌芽的課題 「基礎科学の挑戦」・「極限マテリアル」合同公開シンポジウム　2018/07

  33. 水潤滑下における炭化ケイ素と窒化ケイ素のなじみ過程の違い: 第一原理分子動力学シミュレーション解析

    大谷優介, 中村文哉, 久保百司

    トライボロジー会議2018春東京　2018/05

  34. Tribochemical Wear of Silicon-Based Materials Mediated by Proton Transfer: Molecular Dynamics Sliding Simulation Analysis Invited

    Yusuke Ootani

    2018 HYDROGENIUS & I2CNER TRIBOLOGY SYMPOSIUM　2018/02

  35. First-Principles Molecular Dynamics Study on Chemical Reaction of Silicon-Based Materials Induced by Friction

    Y. Ootani, M. Kubo

    International Symposium "Theoretical Design of Materials with Innovative Functions Based on Element Strategy and Relativistic Electronic Theory"　2017/12

  36. 酸・塩基性溶液がケイ素系材料の摩耗に与える影響：第一原理分子動力学シミュレーション解析

    大谷優介, 高橋直己, 久保百司

    トライボロジー会議2017秋高松　2017/11

  37. 摩擦によって誘起される化学反応がケイ素系セラミックスの摩擦・摩耗に与える影響：第一原理分子動力学解析

    大谷優介, 久保百司

    コンピュータ化学会秋季年会　2017/10

  38. Large-Scale Multi-Physics Computational Simulation for Materials Design

    Y. Ootani, J. Xu, N. Ozawa, M. Kubo

    Tohoku-Melbourne Symposium on Advanced Materials••• Scientific & Engineering Challenges, Part 4　2017/09

  39. First-Principles Molecular Dynamics Simulations for Tribochemical Reactions in Silicon Based Ceramics Sliding Interface

    Y. Ootani, N. Takahashi, M. Kubo

    6th World Tribology Congress　2017/09

  40. ケイ素材料の摩擦界面における水の役割: 第一原理分子動力学計算による化学反応機構解析

    大谷優介, 高橋直己, 久保百司

    トライボロジー会議2017春東京　2017/05

  41. Ru色素・Ru/有機混合色素を用いた色素増感太陽電池の電極表面構造の第一原理計算解析 Invited

    大谷優介

    平成28年度日本表面科学会東北・北海道支部講演会　2017/03

  42. 第一原理分子動力学法による結晶性シリカ摩擦界面の構造と電子状態の解析

    大谷優介, 高橋直己, 久保百司

    トライボロジー会議2016秋新潟　2016/10

  43. Density Functional Theory Study on the Atomic Scale Electrode Interface Structure of the Dye-Sensitized Solar Cells: Ru Dye and Ru/Organic Dye System Invited

    Yusuke Ootani

    Energy, Materials, and Nanotechnology (EMN) Photovoltaics Meeting 2016　2016/01

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Research Projects 6

  1. 濃厚ポリマーブラシの内包水異常性の解明と防着雪氷霜機能応用

    辻井 敬亘

    Offer Organization: 日本学術振興会

    System: 科学研究費助成事業

    Category: 基盤研究(A)

    Institution: 京都大学

    2024/04 - 2027/03

  2. 超低摩擦ポリマーブラシの摩耗現象の階層的理解と制御 Competitive

    Offer Organization: 科学技術振興機構

    System: Core Research for Evolutionary Science and Technology (CREST)

    2021/10 - 2026/03

  3. 変形・破壊の分子ダイナミクスがもたらす力学作用と光の相互変換

    大谷 優介

    Offer Organization: 日本学術振興会

    System: 科学研究費助成事業

    Category: 基盤研究(B)

    Institution: 東北大学

    2022/04 - 2025/03

    More details Close

    分子結晶がもつ力学作用(変形・破壊)と光の相互変換機能が新たなセンサー材料のシーズとして注目されている。この機能は、分子の電子励起状態ダイナミクスが駆動源となり、結晶の秩序高い構造を通して発現する。本研究では、電子励起状態ダイナミクスのための深層学習分子動力学(深層学習MD)手法を開発し、変形・破壊の電子励起状態分子ダイナミクスがもたらす力学作用と光の相互変換機構を解明することを目的とする。具体的には光に応答して力学機能(変形・破壊)を発現するフォトメカニクスと、力学作用(変形・破壊)に応答して発光するメカノルミネッセンスを対象とし、機能発現メカニズムを明らかにする。 本年度はまず、大規模な電子励起状態ダイナミクスを解析するための深層学習MDソフトウェアの開発に取り組んだ。深層学習MDは、深層学習を用いて分子構造から系のエネルギーを予測することで、高い精度を保ちつつ、大規模な分子動力学(MD)シミュレーションを実現する手法であり、大規模解析が必要な分子結晶の変形・破壊の解析に適した手法である。Allegroモデルに基づく深層学習ポテンシャルを実装したソフトウェアを開発し、データの作成、学習、精度の検証といった深層学習MDに必要な機能の実証を完了した。 続いて、深層学習ポテンシャルの学習に必要な電子励起状態のデータを大量に作成するための密度汎関数強束縛分子動力学(DFTB-MD)ソフトウェアの開発を行なった。第一原理分子動力学法による電子励起状態のデータ作成には膨大な計算コストを要する。そのため、本研究は第一原理分子動力学法よりも高速に計算が可能なDFTB-MD法を採用した。本年度は、独自に開発したDFTB-MDソフトウェアに電子励起状態のエネルギー勾配の計算機能を実装した。これにより電子励起状態MDシミュレーションを通して電子励起状態データの大量生成が可能になった。

  4. Chemical Reaction Dynamics in Friction-induced Self-organization and Self-healing of Tribofilms

    Ootani Yusuke

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)

    Category: Grant-in-Aid for Scientific Research (C)

    Institution: Tohoku University

    2019/04 - 2022/03

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    In this work, we performed molecular dynamics-based sliding simulations to investigate the atomic-scale phenomena at sliding interfaces. Accurate first-principles molecular dynamics simulation elucidated the mechanically induced chemical reaction dynamics at the sliding interface. It also showed that the different electronic structure of sliding materials can lead to the different frictional property. In addition, large-scale reactive molecular dynamics simulation clarified the atomic-scale mechanism of the self-formation, wear, and self-healing process of lubricant films.

  5. First-Principles Study on Chemical Reactions Induced by Friction: Design of Low Friction and Wear Resistance Materials

    Ootani Yusuke

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research Grant-in-Aid for Young Scientists (B)

    Category: Grant-in-Aid for Young Scientists (B)

    Institution: Tohoku University

    2017/04/01 - 2019/03/31

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    Reduction of friction is strongly required to reduces the energy loss of machines. Thus, recently, chemical reaction induced by friction is attracted much attention as a low friction technique. In this work, we investigated the chemical reaction mechanism induced by friction and proposed the design principles of low friction sliding materials. We developed quantum chemistry based friction simulator and applied it to chemical reaction at the sliding interface of silicon based materials. We elucidated the chemical reaction mechanism at sliding interface and following super-low friction mechanism by combining an accurate molecular dynamics method and large-scale molecular dynamics method. Moreover, we verified our simulation results by friction experiments and proposed the design principles of low friction materials.

  6. 相対論的ab initio分子動力学手法の開発と重原子分子反応への適用

    大谷 優介

    Offer Organization: 日本学術振興会

    System: 科学研究費助成事業 特別研究員奨励費

    Category: 特別研究員奨励費

    Institution: 北海道大学

    2009 - 2010

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    本年度は分子シミュレーション手法のひとつであるAb initio分子動力学(AIMD)法とMakri-Millerの半古典法を組み合わせ、トンネル効果を見積もる汎用的な手法の開発を行った。 AIMD法はab initio電子状態計算から得られるエネルギー勾配をもとに原子核のニュートンの運動方程式を解くことによって分子シミュレーションを行う方法である。ポテンシャル関数を必要とせず、任意の化学反応へ適用可能な汎用的な手法であるが、原子核を古典的に扱っているという欠点がある。原子核は電子に比べ数千倍のオーダーで重く、量子効果はそれほど大きくないため原子核を古典的に取り扱うことがよい近似になるが、水素のように軽い原子ではその量子効果が化学反応に重要な役割をはたす。特にトンネル効果は水素移動反応や、プロトン移動反応で重要になる。しかし、原子核を量子的に扱うシミュレーションは膨大な計算コストを要するために非常に小さな分子に限られているため、AIMD法の枠組みで適切にトンネル効果を見積もる手法が求められている。 本研究ではトンネル効果を考慮する方法として、Makri-Millerの半古典法を採用した。Makri-Millerの半古典法はシンプルかつ計算コストも大きくないことから、大きな分子や計算コストを要する電子励起状態への適用が期待できる方法である。これまではあらかじめ決定したポテンシャル関数を用いて応用計算が行われてきたが、AIMD法と組合せ、on-the-flyでポテンシャルエネルギーを計算することによって、さらに汎用性の高い手法になる。Makri-Millerの半古典法をAIMDコードに実装し、アンモニアの傘反転反応とマロンアルデヒドの分子内水素移動反応へ適用した。シミュレーションの初期条件、トンネル経路、転回点の決定について適切な条件を検証し、トンネル分裂の計算を行なった。計算結果は定量的に実験値を再現し、トンネル分裂を低コストで見積もる手法の開発に成功した。 本研究の成果は近日Journal of Computational Chemistryへの投稿を予定している。

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Teaching Experience 12

  1. Computational Materials Science　Tohoku University

  2. Quantum chemistry　Tohoku University

  3. 学問論演習(シミュレーションとの付き合い方)

  4. 量子化学　東北大学

  5. 准教授セミナー (分子動力学法セミナー)　東北大学

  6. Computational Materials Science　Tohoku University

  7. 量子化学　東北大学

  8. Computational Materials Science　Tohoku University

  9. 量子化学　東北大学

  10. Molecular Dynamics Simulation Seminar　Tohoku University

  11. Computational Materials Science　Tohoku University

  12. Quantum Chenistry　Tohoku University

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Works 2

  1. FSEC: Density Functional Tight-binding Molecular Dynamics software

    Type: Software

  2. NTChem用ab initio分子動力学計算プログラム

    大谷優介

    Type: Software

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    https://molsc.riken.jp/software.html#lwNTChem

Other 1

  1. Completion of the Future Principal Investigator Program