1k citations
Counting papers with at most 25 authors, so collaboration author lists do not stand in for the people here.
- The Graduate University for Advanced Studies, SOKENDAIJP143 papers
- National Institutes of Natural SciencesJP76 papers
- The University of TokyoJP75 papers
- The University of OsakaJP59 papers
- Kyoto UniversityJP52 papers
- Tohoku UniversityJP46 papers
- Japan Science and Technology AgencyJP32 papers
- Nagoya UniversityJP30 papers
- Hiroshima UniversityJP27 papers
- High Energy Accelerator Research OrganizationJP26 papers
- RIKENJP26 papers
- Tokyo Institute of TechnologyJP26 papers
40 papers · 1 filter
Analytical Nuclear Gradients for State-Averaged Configuration Interaction Singles Variants: Application to Conical Intersections
Takashi Tsuchimochi
We derive analytical nuclear gradients for state-averaged orbital-optimized configuration interaction singles (SACIS) and its spin-projected extension (SAECIS), enabling efficient…
Deep learning of committor and explainable artificial intelligence analysis for identifying reaction coordinates
Toshifumi Mori, Kei-ichi Okazaki, Kang Kim +1
In complex molecular systems, the reaction coordinate (RC) that characterizes transition pathways is essential to understand underlying molecular mechanisms. This review surveys a…
Leveraging configuration interaction singles for qualitative descriptions of ground and excited states: state-averaging, linear-response, and spin-projection
Takashi Tsuchimochi, Benjamin Mokhtar
While configuration interaction singles (CIS) provides a computationally efficient description of excited states, it systematically overestimates excitation energies and performs p…
Deep learning of committor for ion dissociation and interpretable analysis of solvent effects using atom-centered symmetry functions
Kenji Okada, Kazushi Okada, Kei-ichi Okazaki +3
The association and dissociation of ion pairs in water are fundamental to physical chemistry, yet their reaction coordinates are complex, involving not only interionic distance but…
Double Configuration Interaction Singles: Scalable and size-intensive approach for orbital relaxation in excited states and bond-dissociation
Takashi Tsuchimochi
We present a novel theoretical scheme for orbital relaxation in configuration interaction singles (CIS) based on a perturbative treatment of its electronic Hessian, whose analytica…
Investigating the hyperparameter space of deep neural network models for reaction coordinates
Kyohei Kawashima, Takumi Sato, Kei-ichi Okazaki +3
Identifying reaction coordinates (RCs) is a key to understanding the mechanism of reactions in complex systems. Deep neural network (DNN) and machine learning approaches have becom…
Unveiling interatomic distances influencing the reaction coordinates in alanine dipeptide isomerization: An explainable deep learning approach
Kazushi Okada, Takuma Kikutsuji, Kei-ichi Okazaki +3
The present work shows that the free energy landscape associated with alanine dipeptide isomerization can be effectively represented by specific interatomic distances without expli…
Pathway selectivity in time-resolved spectroscopy using two-photon coincidence counting with quantum entangled photons
Yuta Fujihashi, Akihito Ishizaki, Ryosuke Shimizu
Ultrafast optical spectroscopy is a powerful technique for studying the dynamic processes of molecular systems in condensed phases. However, in molecular systems containing many dy…
A theory of chemical Reactions in biomolecules in solution: generalized Langevin mode analysis (GLMA)
Fumio Hirata
The generalized Langevin mode analysis (GLMA) is applied to chemical reactions in biomolecules in solution. The theory sees a chemical reaction in solution as a barrier crossing pr…
Probing exciton dynamics with spectral selectivity through the use of quantum entangled photons
Yuta Fujihashi, Kuniyuki Miwa, Masahiro Higashi +1
Quantum light is increasingly recognized as a promising resource for developing optical measurement techniques. Particular attention has been paid to enhancing the precision of the…
Explaining reaction coordinates of alanine dipeptide isomerization obtained from deep neural networks using Explainable Artificial Intelligence (XAI)
Takuma Kikutsuji, Yusuke Mori, Kei-ichi Okazaki +3
A method for obtaining appropriate reaction coordinates is required to identify transition states distinguishing product and reactant in complex molecular systems. Recently, abunda…
The initial charge separation step in oxygenic photosynthesis
Yusuke Yoneda, Eric A. Arsenault, Kaydren Orcutt +2
Photosystem II is crucial for life on Earth as it provides oxygen as a result of photoinduced electron transfer and water splitting reactions. The excited state dynamics of the pho…
Specific chemical bond relaxation unravelled by analysis of shake-up satellites in the oxygen single site double core hole spectrum of CO
Anthony Ferté, Francis Penent, Jérôme Palaudoux +7
We developed recently [A. Ferté, et al., J. Phys. Chem. Lett. 11, 4359 (2020)] a method to compute single site double core hole (ssDCH or K) spectra. We refer to that method…
Achieving two-dimensional optical spectroscopy with temporal and spectral resolution using quantum entangled three photons
Yuta Fujihashi, Akihito Ishizaki
Recent advances in techniques for generating quantum light have stimulated research on novel spectroscopic measurements using quantum entangled photons. One such spectroscopy techn…
IR photofragmentation of the Phenyl Cation: Spectroscopy and Fragmentation Pathways
S. D. Wiersma, A. Candian, J. M. Bakker +5
We present the gas-phase infrared spectra of the phenyl cation, phenylium, in its perprotio CH and perdeutero CD forms, in the 260-1925 cm (5.2-38 m)…
Insights into photosynthetic energy transfer gained from free-energy structure: Coherent transport, incoherent hopping, and vibrational assistance revisited
Akihito Ishizaki, Graham R. Fleming
Giant strides in ultrashort laser pulse technology have enabled real-time observation of dynamical processes in complex molecular systems. Specifically, the discovery of oscillator…
Learning reaction coordinates via cross-entropy minimization: Application to alanine dipeptide
Yusuke Mori, Kei-ichi Okazaki, Toshifumi Mori +2
We propose a cross-entropy minimization method for finding the reaction coordinate from a large number of collective variables in complex molecular systems. This method is an exten…
Prerequisites for relevant spectral density and convergence of reduced density matrices at low temperatures
Akihito Ishizaki
Hierarchical equations of motion approach with the Drude-Lorentz spectral density has been widely employed in investigating quantum dissipative phenomena. However, it is often comp…
Intramolecular Vibrations Complement the Robustness of Primary Charge Separation in a Dimer Model of the Photosystem II Reaction Center
Yuta Fujihashi, Masahiro Higashi, Akihito Ishizaki
The energy conversion of oxygenic photosynthesis is triggered by primary charge separation in proteins at the photosystem II reaction center. Here, we investigate the impacts of th…
Control of Excitation Energy Transfer in Condensed Phase Molecular Systems by Floquet Engineering
Nguyen Thanh Phuc, Akihito Ishizaki
Excitation energy transfer (EET) is one of the most important processes in both natural and artificial chemical systems including, for example, photosynthetic complexes and organic…
Hyperfine coupling constants from internally contracted multireference perturbation theory
Toru Shiozaki, Takeshi Yanai
We present an accurate method for calculating hyperfine coupling constants (HFCCs) based on the complete active space second-order perturbation theory (CASPT2) with full internal c…
A screened automated structural search with semiempirical methods
Yukihiro Ota, Sergi Ruiz-Barragan, Masahiko Machida +1
We developed an interface program between a program suite for an automated search of chemical reaction pathways, GRRM, and a program package of semiempirical methods, MOPAC. A two-…
On the hierarchical parallelization of ab initio simulations
Sergi Ruiz-Barragan, Kazuya Ishimura, Motoyuki Shiga
A hierarchical parallelization has been implemented in a new unified code PIMD-SMASH for ab initio simulation where the replicas and the Born-Oppenheimer forces are parallelized. I…
Concatenated Composite Pulses Applied to Liquid-State Nuclear Magnetic Resonance Spectroscopy
Masamitsu Bando, Tsubasa Ichikawa, Yasushi Kondo +3
The error-robust and short composite operations named ConCatenated Composite Pulses (CCCPs), developed as high-precision unitary operations in quantum information processing (QIP),…