A5045907415- Advanced Chemical Physics Studies
- Spectroscopy and Quantum Chemical Studies
- Atomic and Molecular Physics
- Photochemistry and Electron Transfer Studies
- Advanced NMR Techniques and Applications
- Photosynthetic Processes and Mechanisms
- Molecular Junctions and Nanostructures
- Magnetism in coordination complexes
- Nanoplatforms for cancer theranostics
- Photodynamic Therapy Research Studies
- Crystallography and molecular interactions
- X-ray Diffraction in Crystallography
- Metal-Catalyzed Oxygenation Mechanisms
- Machine Learning in Materials Science
- Inorganic Fluorides and Related Compounds
- Molecular spectroscopy and chirality
- Perovskite Materials and Applications
- Crystallization and Solubility Studies
- Molecular Spectroscopy and Structure
- Computational Drug Discovery Methods
- Protein Structure and Dynamics
- Catalytic Processes in Materials Science
- Advanced Physical and Chemical Molecular Interactions
- Quantum and electron transport phenomena
- Quantum Dots Synthesis And Properties
RIKEN Center for Computational Science
2016-2025
RIKEN
2025
Kyoto University
1997-2024
Panasonic (Japan)
2023-2024
Materials Science & Engineering
2023-2024
Université Grenoble Alpes
2020-2023
University of Bristol
2023
UiT The Arctic University of Norway
2023
The Abdus Salam International Centre for Theoretical Physics (ICTP)
2023
Bridge University
2023
Specialized computational chemistry packages have permanently reshaped the landscape of chemical and materials science by providing tools to support guide experimental efforts for prediction atomistic electronic properties. In this regard, structure played a special role using first-principle-driven methodologies model complex processes. Over past few decades, rapid development computing technologies tremendous increase in power offered unique chance study transformations sophisticated...
The higher-order Douglas–Kroll (DK) Hamiltonians in an external potential are explicitly derived. Application of exponential-type unitary operator with the 2n+1 rule significantly simplifies formulations high-order DK Hamiltonians. third-order method has been implemented practically. Numerical results for one- and many-electron systems show that good accuracy can be obtained even Hamiltonian correct to third order potential.
We performed a systematic high-throughput simulation with density functional theory for 11 025 compositions of hybrid organic-inorganic halide compounds in ABX3 and A2BB'X6 forms, where A is an organic or inorganic component, B/B' metal atom, X halogen atom. The computational results were compiled as materials database. massive by using the K computer, which massively parallel many-core supercomputer Japan. By applying screening procedure to all database, we discovered novel candidates...
Using time-dependent density functional theory (TD-DFT), configuration interaction single (CIS) method, and approximate coupled cluster singles doubles (CC2) we investigated the absorption spectra of coumarin derivative dyes (C343, NKX-2388, NKX-2311, NKX-2586, NKX-2677), which have been synthesized for efficient dye-sensitized solar cells. The CC2 calculations are found in good agreement with experimental results except smallest dye (C343). TD-DFT underestimates vertical excitation energy...
The BigDFT project was started in 2005 with the aim of testing advantages using a Daubechies wavelet basis set for Kohn–Sham (KS) density functional theory (DFT) pseudopotentials. This led to creation code, which employs computational approach optimal features flexibility, performance, and precision results. In particular, employed formalism has enabled implementation an algorithm able tackle DFT calculations large systems, up many thousands atoms, effort that scales linearly number atoms....
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Well-crystallized CsSnI 3 thin films can be easily obtained through two-step thermal annealing at low temperatures of 40 °C and 70 °C.
An assessment of low-cost computational chemistry methods reveals the outstanding performance XTB1 for calculating relative binding energies chemically similar systems, notably conformers substrates in enzyme active sites.
In recent years, perovskites have quickly gained popularity in applications related to photonic devices and photovoltaic applications. Over the last several efficiency of (PV) cells based on has matched PV silicon. CsPbBr3 perovskite is gaining more popularity, but due too large band gap value, its use photovoltaics difficult. Another perovskite, very intensively researched giving hope for further development photovoltaics, CsPbI3. The CsPbI3 smaller than suitable However, unstable under...
Highly accurate relativistic Gaussian basis sets are developed for the 103 elements from H(Z=1) to Lr (Z=103). Orbital exponents optimized by minimizing atomic self-consistent field (SCF) energy with scalar third-order Douglas–Kroll approximation. The designed have equal quality and be appropriate incorporation of effects. set performance is tested calculations on prototypical molecules, hydrides, dimers copper, silver, gold using SCF, Møller–Plesset theory, singles doubles coupled-cluster...
The adsorption energies and structures of methanethiolate, SCH3, on the (111) surfaces Au, Ag, Cu have been studied using a density functional theory. results obtained for Au surface are in good agreement with experiments previous calculations. strength is found to be Cu>Ag>Au, nature chemisorption bond discussed. strong interaction between SCH3 can explained similar way that as binding energy metal atoms. Scalar-relativistic effects structures, which dominate differences...
A new class of heterogeneous catalytic systems utilizing cation-guest interactions was designed based on microporous titanosilicate molecular sieves. Introducing heavier alkali metal cations ion-exchange sites the framework resulted in a significant enhancement activity for oxidation cyclohexene and styrene, whereas such an not observed cyclohexane without π systems. Distinct relationships between activities intermolecular interaction energies which were determined by IR spectroscopic...
The theoretical and technical foundations are presented for the efficient relativistic electronic structure theories to treat heavy-atomic molecular systems. This review contains two surveys of four-component two-component quasi-relativistic approaches. First, we our highly computational scheme ab initio orbital (MO) methods over generally contracted spherical harmonic Gaussian-type spinors (GTSs). Illustrative calculations, which performed with a new program package REL4D, clearly show...
In this Software News, the authors introduce NTChem, a new comprehensive software package developed in Japan, for ab initio quantum chemistry calculations. It includes various high‐performance computational methods and functions molecular simulations. Furthermore, it is designed calculations on computer with numerous compute nodes. Therefore, makes optimum use of K computer's processing power. This News specifically examines parallel performance NTChem computer. © 2014 Wiley Periodicals, Inc.
We investigate laccase-mediated detoxification of aflatoxins, fungal carcinogenic food contaminants. Our experimental comparison between two aflatoxins with similar structures (AFB1 and AFG2) shows significant differences in detoxification. A multi-scale modeling approach (Docking, Molecular Dynamics, Density Functional Theory) identifies the highly substrate-specific changes required to improve laccase detoxifying performance. employ a large-scale density functional theory-based approach,...
A highly efficient computational scheme for four-component relativistic ab initio molecular orbital (MO) calculations over generally contracted spherical harmonic Gaussian-type spinors (GTSs) is presented. Benchmark the ground states of group IB hydrides, MH, and dimers, M2 (M=Cu, Ag, Au), by Dirac–Hartree–Fock (DHF) method were performed with a new MO program package oriented toward GTSs. The electron repulsion integrals (ERIs), major bottleneck in routine DHF calculations, are calculated...
A new generalized Douglas–Kroll (DK) approach is proposed for the relativistic many-electron Hamiltonian including electron–electron interaction. In order to consider higher-order DK transformation two-electron interaction, present adopts effective one-electron potential in Dirac–Hartree–Fock/Dirac–Kohn–Sham operator as an expansion parameter transformation. Its numerical performance tested atomic Hg and molecular HAt At2 systems. The third-order both Hamiltonians, which highest level of...
Coupled-cluster methods including through and up to the connected single, double, triple, quadruple substitutions have been derived implemented automatically for sequential parallel executions by an algebraic symbolic manipulation program TCE (TENSOR CONTRACTION ENGINE) use in conjunction with a one-component third-order Douglas-Kroll approximation relativistic corrections. A combination of converging electron-correlation methods, accurate reference wave functions, systematic basis sets...
Anharmonic vibrational analysis of near-infrared (NIR) spectra acetic acid was carried out by anharmonic quantum chemical calculation in a wide concentration range its CCl4 solution. By predicting for the first time over NIR region, it possible to elucidate influence formation cyclic dimer on spectrum. Quantum simulations were based coupled cluster and density functional theory methods. Additionally, Møller-Plesset perturbation employed additional hydrogen bonding stabilization energies. An...
Abstract The synthesis of highly negatively charged polyoxometalates with electrically and structurally controlled uniform basic sites can lead to the unique base catalysis. In this work, a γ‐Keggin germanodecatungstate, [γ‐HGeW 10 O 36 ] 7− ( A ), having −7 charge was, for first time, successfully synthesized by reaction [γ‐H 2 GeW 6− one equivalent [(n‐C 4 H 9 ) N]OH under non‐aqueous conditions. activities germanodecatungstates base‐catalyzed reactions dramatically increased increase in...
We have carried out large-scale computational quantum chemistry calculations on the K computer to obtain heats of formation for C60 and some higher fullerenes with DSD-PBE-PBE/cc-pVQZ double-hybrid density functional theory method. Our best estimated values are 2520.0 ± 20.7 (C60), 2683.4 17.7 (C70), 2862.0 18.5 (C76), 2878.8 13.3 (C78), 2946.4 14.5 (C84), 3067.3 15.4 (C90), 3156.6 16.2 (C96), 3967.7 33.4 (C180), 4364 (C240) 5415 (C320) kJ mol(-1). In our assessment, we also find that...
Abstract In the past decade, developments of computational technology around density functional theory (DFT) calculations have considerably increased system sizes which can be practically simulated. The advent robust high performance computing algorithms scale linearly with size has unlocked numerous opportunities for researchers. This fact enables physicists and chemists to investigate systems are comparable routinely considered by experimentalists, leading collaborations a wide range...
The core ionization energies of the second-period and third-period elements are studied by ΔSCF Slater's transition state (STS) theory using Hartree-Fock (HF) Kohn-Sham (KS) approximations. Electron correlation increases estimated energies, while self-interaction error (SIE) decreases them, especially for is a more significant factor. As result, HF lacks electron correlation, it free SIE reasonably predicts energies. calculated STS very close to those ΔSCF, showing that describes relaxation...