About the Research
Research Theme
Elucidating molecules and reactions with computational chemistry and data science
Keyword
Research Outline
Our goal is to predict structure, properties, and reactions of materials with computer.
Every material consists of electrons and nuclei. Very small substance such as electron behaves according to “quantum mechanics.” If we can solve the Schroedinger equation, which is the basic equation of the quantum mechanics, on computers, we can achieve our goal! But, it is not so easy. The number of electrons tructable in a calculation is limited because even the simplest method requires the computational time proportional to the 3rd power of the number of electrons. We are tackling to the prediction of the behavior of huge molecules (over 1 million atom in some cases) by using the divideandconquer (DC) method, which is an advanced computational technique, and massively parallel computers like K computer.
It is, however, still difficult to describe the real chemical world involving Avogadro number atoms. So, we are importing “informatics” and/or “artificial intelligence” and are trying to elucidate and predict the catalytic reaction mechanisms and efficiency.
Representative Research Achievements
 A Combined Automated Reaction Pathway Searches and Sparse Modeling Analysis for Catalytic Properties of Lowest Energy Twins of Cu_{13}
T. Iwasa, T. Sato, M. Takagi, M. Gao, A. Lyalin, M. Kobayashi, K.i. Shimizu, S. Maeda, and T. Taketsugu, J. Phys. Chem. A, 2019, 123, 210217
DOI: 10.1021/acs.jpca.8b08868  Automated Error Control in DivideandConquer SelfConsistent Field Calculations
M. Kobayashi, T. Fujimori, and T. Taketsugu, J. Comput. Chem., 2018, 38, 909916. (Cover Article)
DOI: 10.1002/jcc.25174  DivideandConquer Hartree–Fock–Bogoliubov Method and Its Application to Conjugated Diradical Systems
M. Kobayashi and T. Taketsugu, Chem. Lett., 2016, 45, 12681270
DOI: 10.1246/cl.160699  Three Pillars for Realizing Quantum Mechanical Molecular Dynamics Simulations of Huge Systems: DivideandConquer, Density Functional TightBinding, and Massively Parallel Computation
H. Nishizawa, Y. Nishimura, M. Kobayashi, S. Irle, and H. Nakai, J. Comput. Chem., 2016, 37, 19831992
DOI: 10.1002/jcc.24419  Alternative LinearScaling Methodology for the SecondOrder MøllerPlesset Perturbation Calculation Based on the DivideandConquer Method
M. Kobayashi, Y. Imamura, and H. Nakai, J. Chem. Phys., 2007, 127, 074103
DOI: 10.1063/1.2761878
Related Research
 Polymer chain molecule arrangement influences circularly polarized light emission properties
 A joint research project with researchers of Hokkaido University has been published in ChemPlusChem
Publications
2024

Theoretical Design and Synthesis of Caged Compounds Using XRayTriggered Azo Bond Cleavage
, O. Inanami, H. Takakura, K. Saita, K. Nakajima, S. Kumar, N. Ieda, M. Kobayashi, T. Taketsugu, M. Ogawa, Advanced Science, 2024, ,
DOI: 10.1002/advs.202306586
2023

Reproducing the Reaction Route Map on the Shape Space from Its Quotient by the Complete Nuclear PermutationInversion Group
, T. Saito, M. Aoki, B. Murayama, M. Kobayashi, T. Nakamura, T. Taketsugu, J. Chem. Theory Comput., 2023, 19, 17, 5886–5896
DOI: 10.1021/acs.jctc.3c00500

Computational Survey of Humin Formation from 5(hydroxymethyl)furfural under Basic Conditions
, M. Kobayashi, K. Nakajima, T. Taketsugu, RSC Advances, 2023, 13, 1629316299
DOI: 10.1039/d3ra02870d

TimeDependent HartreeFockBogoliubov Method for Molecular Systems: An Alternative ExcitedState Methodology Including Static Electron Correlation
, T. Akama, M. Kobayashi, T. Taketsugu, Chemical Physics Letters, 2023, 816, 140386
DOI: 10.1016/j.cplett.2023.140386

DivideandConquer LinearScaling Quantum Chemical Computations
, M. Kobayashi, T. Yoshikawa, J. Seino, Y. Ikabata, Y. Nishimura, J. Phys. Chem. A, 2023, 127, 3, 589–618
DOI: 10.1021/acs.jpca.2c06965
2022

Ligand Release from Silicon Phthalocyanine Dyes Triggered by XRay Irradiation
, S. Matsuhiro, O. Inanami, M. Kobayashi, K. Saita, M. Yamashita, K. Nakajima, M. Suzuki, N. Miyamoto, T. Taketsugu, M. Ogawa, Org. Biomol. Chem., 2022, 20, 72707277
DOI: 10.1039/d2ob00957a

Effective Photosensitization in ExcitedState Equilibrium: Brilliant Luminescence of TbIII Coordination Polymers Through Ancillary Ligand Modifications
, R. Moriake, T. Akama, K. Saito, K. Aikawa, S. Shoji, K. Fushimi, M. Kobayashi, T. Taketsugu, Y. Hasegawa, ChemPlusChem, 2022, ,
DOI: 10.1002/cplu.202200151

Asymmetric LuminoTransformer: Circularly Polarized Luminescence of Chiral Eu(III) Coordination Polymer with PhaseTransition Behavior
, Y. Kitagawa, S. Shoji, H. Ohmagari, M. Hasegawa, M. Gon, K. Tanaka, M. Kobayashi, T. Taketsugu, K. Fushimi, Y. Hasegawa, J. Phys. Chem. B, 2022, 126, 37993807
DOI: 10.1021/acs.jpcb.2c01639

Practical Electronic Groundand ExcitedState Calculation Method for Lanthanide Complexes Based on Frozen Core Potential Approximation to 4f Electrons
, Y. Oba, T. Akama, T. Taketsugu, Journal of Mathematical Chemistry, 2022, ,
DOI: 10.1007/s10910022013565

AxialLigandCleavable Silicon Phthalocyanines Triggered by NearInfrared Light Toward Design of Photosensitizers for Photoimmunotherapy
, S. Matsuhiro, M. Kobayashi, Y. Goto, M. Harada, T. Taketsugu, M. Ogawa, Journal of Photochemistry and Photobiology aChemistry, 2022, 426,
DOI: 10.1016/j.jphotochem.2021.113749
2021

Automatic Determination of Buffer Region in DivideAncConquer Quantum Chemical Calculations
, T. Fujimori, T. Taketsugu, Journal of Computer ChemistryJapan, 2021, 20, 4859
DOI: 10.2477/jccj.20210025

EnergyBased Automatic Determination of Buffer Region in the DivideandConquer SecondOrder MollerPlesset Perturbation Theory
, M. Kobayashi, T. Taketsugu, Journal of Computational Chemistry, 2021, 42, 620629
DOI: 10.1002/jcc.26486

Coordination Geometrical Effect on LigandtoMetal Charge TransferDependent Energy Transfer Processes of Luminescent Eu(III) Complexes
, S. Miyazaki, H. Sakamoto, Y. Kitagawa, K. Miyata, T. Akama, M. Kobayashi, K. Fushimi, K. Onda, T. Taketsugu, Y. Hasegawa, J. Phys. Chem. A, 2021, 125, 209217
DOI: 10.1021/acs.jpca.0c09337
2020

AllElectron Relativistic SpinOrbit Multireference Computation to Elucidate the Ground State of CeH
, Y. Goto, M. Kobayashi, T. Akama, T. Noro, T. Taketsugu, Phys. Chem. Chem. Phys., 2020, 22, 2715727162
DOI: 10.1039/d0cp05070a

Theoretical and Experimental Studies on the NearInfrared Photoreaction Mechanism of a Silicon Phthalocyanine Photoimmunotherapy Dye: Photoinduced Hydrolysis by Radical Anion Generation
, M. Harada, H. Takakura, K. Ando, Y. Goto, T. Tsuneda, M. Ogawa, T. Taketsugu, ChemPlusChem, 2020, 85, 19591963
DOI: 10.1002/cplu.202000338
2019

Combined Automated Reaction Pathway Searches and Sparse Modeling Analysis for Catalytic Properties of Lowest Energy Twins of Cu_{13}
, T. Sato, M. Takagi, M. Gao, A. Lyalin, M. Kobayashi, K. Shimizu, S. Maeda, T. Taketsugu, J. Phys. Chem. A, 2019, 123, 210217
DOI: 10.1021/acs.jpca.8b08868