A5053454625- Advanced Chemical Physics Studies
- Quantum Computing Algorithms and Architecture
- Quantum Information and Cryptography
- Machine Learning in Materials Science
- Organic Chemistry Cycloaddition Reactions
- Spectroscopy and Quantum Chemical Studies
- Manufacturing Process and Optimization
- Quantum and electron transport phenomena
- Organometallic Complex Synthesis and Catalysis
- Particle physics theoretical and experimental studies
- Chemical Reactions and Isotopes
- Innovative Microfluidic and Catalytic Techniques Innovation
- Inorganic and Organometallic Chemistry
- Chemistry and Chemical Engineering
- Oxidative Organic Chemistry Reactions
- Advanced Physical and Chemical Molecular Interactions
- High-Energy Particle Collisions Research
- Quantum Chromodynamics and Particle Interactions
- Neural Networks and Reservoir Computing
- Catalysis and Oxidation Reactions
- Quantum-Dot Cellular Automata
- Chemical Thermodynamics and Molecular Structure
- Various Chemistry Research Topics
- Molecular Spectroscopy and Structure
- CO2 Reduction Techniques and Catalysts
JSR (Japan)
2024-2025
Yokkaichi University
2023
Keio University
2002-2022
Kobe University
2013-2017
University of Illinois Urbana-Champaign
2011-2017
Max Planck Institute for Solid State Research
2017
University of Florida
2010-2012
Kyoto University
2005-2011
Osaka University
1991-2005
Nippon Steel (Japan)
2004
Ruthenium-catalyzed hydrogenation of carbon dioxide to formic acid was theoretically investigated with DFT and MP4(SDQ) methods, where a real catalyst, cis-Ru(H)2(PMe3)3, employed in calculations compared model cis-Ru(H)2(PH3)3. Significant differences between the systems are observed CO2 insertion into Ru(II)-H bond, isomerization ruthenium(II) eta1-formate intermediate, metathesis intermediate dihydrogen molecule. All these reactions more easily occur system than system. The interpreted...
We report on the comparison of electronic and photophysical properties a series related donor–acceptor–donor oligomers incorporating previously known 2H-benzo[d][1,2,3]triazole (BTz) moiety as acceptor recently reported BTzTD acceptor, hybrid BTz 2,1,3-benzothiadiazole (BTD). Although often implied in polymer literature that has good character, we show this is best described weak acceptor. present electrochemical, computational, evidence supporting our assertion strong electron while...
We study the photodissociation of sulfonium cation using quantum computing algorithms on IBM's hardware. combine and extend methodologies to compute molecular excited states, spectra, dissociation pathways.
The explicitly correlated approach is one of the most important breakthroughs in ab initio electronic structure theory, providing arguably compact, accurate, and efficient ansatz for describing motion electrons. Since Hylleraas first used an wave function He atom 1929, numerous attempts have been made to tackle significant challenges involved constructing practical methods that are applicable larger systems. These include identifying suitable mathematical forms a evaluation many-electron...
Abstract A quantum chemistry study of the first singlet ( S 1 ) and triplet T excited states phenylsulfonyl-carbazole compounds, proposed as useful thermally activated delayed fluorescence (TADF) emitters for organic light emitting diode (OLED) applications, was performed with Equation-Of-Motion Variational Quantum Eigensolver (qEOM-VQE) Deflation (VQD) algorithms on simulators devices. These simulations were double zeta quality basis sets an active space comprising highest occupied lowest...
We present a quantum-classical hybrid algorithm that simulates electronic structures of periodic systems such as ground states and quasiparticle band structures. By extending the unitary coupled cluster (UCC) theory to describe crystals in arbitrary dimensions, for hydrogen chain, we numerically demonstrate UCC ansatz implemented on quantum circuit can be successfully optimized with small deviation from exact diagonalization over entire range potential energy curves. Furthermore, by using...
Ru-catalyzed hydrogenation of carbon dioxide to formic acid was theoretically investigated with DFT and MP4(SDQ) methods. In the presence water molecules, reaction proceeds as follows: (1) Carbon forms adduct cis-Ru(H)2(PMe3)3(H2O)(CO2), in which C O atoms CO2 interact H (hydride) ligand atom H2O, respectively. (2) Nucleophilic attack takes place easily afford a Ru-(η1-formate) intermediate, Ru(H)(PMe3)3(η1-OCOH)(H2O), much smaller activation barrier than that insertion into Ru−H bond, is...
Transmetalation between palladium(II)-vinyl complex and vinylsilane was theoretically investigated with the DFT MP2 to MP4 methods clarify reaction mechanism reasons why fluoride anion accelerates Pd-catalyzed cross-coupling vinyl iodide vinylsilane. This transmetalation occurs a very large activation barrier (45.8 kcal/mol) endothermicity (25.6 in absence of anion, where potential energy change resulting from solvation effect is evident. consistent experimental fact that this does not...
Nickel(0)-catalyzed phenylcyanation of alkyne was theoretically investigated with the DFT(B3PW91) method to clarify reaction mechanism including formation process active species, rate-determining step, and regioselectivity reaction, where real catalyst Ni(PMe3)2 employed. The first step this is coordination PhCN Ni center followed by isomerization Ni(PMe3)2(PhCN) oxidative addition Ph−CN Ni(0) center. next form a five-coordinate intermediate. PMe3 then dissociates from Ni(II) four-coordinate...
We propose a method to sequentially optimize arbitrary single-qubit gates in parametrized quantum circuits for simulating real- and imaginary-time evolution. The utilizes full degrees of freedom therefore can potentially obtain better performance. Specifically, it simultaneously optimizes both the axis angle gate, while known methods either with fixed, or vice versa. It generalizes sinusoidal cost functions by rotation. Furthermore, we demonstrate how be extended set two-qubit...
We present a quantum-classical hybrid algorithm for calculating the ground state and its energy of quantum many-body Hamiltonian by proposing an adaptive construction quantum-selected configuration interaction (QSCI) method. QSCI allows us to select important electronic configurations in system perform (CI) calculation (subspace diagonalization Hamiltonian) sampling measurement proper input on computer, but how we prepare desirable remains challenge. propose which run repeatedly grow...
This paper presents a wave-function method based on unitary coupled-cluster theory for quantum computers, to determine the circuit parameters and molecular orbital simultaneously, as well molecular-geometry optimizations
The chemical properties of copolymers are strongly influenced by a number intrinsic characteristics such as their molecular weight and monomer composition ratio. Identifying the optimal conditions for copolymerization process that results in synthesized copolymer with desired is major challenge. Optimization has traditionally been based on trial-and-error approaches humans relying em-pirical rules. Thus, design space can be explored experimentally severely limited under time economic...
The chemical properties of copolymers are strongly influenced by a number intrinsic characteristics such as their molecular weight and monomer composition ratio. Identifying the optimal conditions for copolymerization process that results in synthesized copolymer with desired is major challenge. Optimization has traditionally been based on trial-and-error approaches humans relying em-pirical rules. Thus, design space can be explored experimentally severely limited under time economic...
The chemical properties of copolymers are strongly influenced by a number intrinsic characteristics such as their molecular weight and monomer composition ratio. Identifying the optimal conditions for copolymerization process that results in synthesized copolymer with desired is major challenge. Optimization has traditionally been based on trial-and-error approaches humans relying em-pirical rules. Thus, design space can be explored experimentally severely limited under time economic...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPhotocycloaddition of thiocarbonyl compounds to olefins. Reaction thiobenzophenone with styrene and substituted styrenesA. Ohno, Y. Ohnishi, M. Fukuyama, G. TsuchihashiCite this: J. Am. Chem. Soc. 1968, 90, 25, 7038–7043Publication Date (Print):December 1, 1968Publication History Published online1 May 2002Published inissue 1 December 1968https://pubs.acs.org/doi/10.1021/ja01027a027https://doi.org/10.1021/ja01027a027research-articleACS...
Abstract Theoretical and computational methods are powerful in studying transition metal complexes. Our theoretical studies of C–H σ‐bond activation benzene by Pd(II)–formate complex that methane Ti(IV)‐imido successfully disclosed these reactions understood to undergo heterolytic the driving force is formation strong O–H N–H bonds former latter, respectively. Orbital interactions considerably different from those oxidative addition. The transmetallation, which a key process cross‐coupling...
Explicitly correlated second‐order Green's function (GF2‐F12) is presented and applied to polycyclic aromatic hydrocarbons (PAHs), oligothiophene, porphyrins. GF2 suffers from slow convergence of orbital expansions as in the ordinary post Hartree–Fock methods ab initio theory, albeit method capable providing quantitatively accurate ionization energies (IE) near complete basis set limit. This feature significantly mitigated by introducing F12 terms explicitly electronic structure theory. It...
The study utilized machine learning to predict highly accurate polymer properties, mainly when quantum chemical calculation values were included as variables, thus suggesting a promising tool for accelerating development with new monomers.
Oxidative addition of H2 to Ni(PH3)2 was theoretically studied as a prototype nickel-catalyzed sigma-bond activation reaction, where CASSCF, CASPT2, CCSD(T), broken symmetry (Bs) MP2 MP4(SDTQ), and DFT methods were employed. The CASPT2 method yields reliable potential energy curve (PEC) when the active space consists 10 electrons orbitals including five outer 3d' orbitals. CCSD(T) presents almost same PEC CASPT2-calculated one, either ANO or cc-pVTZ basis set is used for Ni....
We propose progressive downsampling of wave vectors in the Brillouin zone integrations occurring second-order many-body or Møller–Plesset perturbation (MP2) method for extended systems one-dimensional periodicity. Higher-lying unoccupied and lower-lying occupied Bloch orbitals are subject to by an exponentially increasing factor (with base n), making total number included MP2 lattice sums grow only logarithmically with respect basis functions per unit cell. Unlike mod n scheme proposed...
A pedagogical proof is presented for the extensivity of energies metallic and nonmetallic crystals that proceeds by elucidating asymptotic distance dependence effective chemical interactions: kinetic, Coulomb, exchange, correlation. On this basis, a guideline size-consistent design electronic vibrational methods proposed. This underscores significance distinct use intermediate standard normalization wave functions extensive intensive quantities, includes diagram theorems as unambiguous...