JOPSS - Search Results

Search Results: Records 1-20 displayed on this page of 24

Presentation/Publication Type

Initialising ...

Refine

Journal/Book Title

Initialising ...

Meeting title

Initialising ...

First Author

Initialising ...

Keyword

Initialising ...

Language

Initialising ...

Publication Year

Initialising ...

Held year of conference

Initialising ...

Journal Articles

A Theoretical investigation on the intermolecular potential curve between ruthenium tetroxide and NO $_{rm X}$ (X = 1, 2)

Kido, Kentaro

International Journal of Quantum Chemistry, 121(21), p.e26781_1 - e26781_15, 2021/11

https://doi.org/10.1002/qua.26781

Times Cited Count：1 Percentile：16.75(Chemistry, Physical)

Journal Articles

Chemical reaction kinetics dataset of Cs-I-B-Mo-O-H system for evaluation of fission product chemistry under LWR severe accident conditions

Miyahara, Naoya; Miwa, Shuhei; Horiguchi, Naoki; Sato, Isamu*; Osaka, Masahiko

Journal of Nuclear Science and Technology, 56(2), p.228 - 240, 2019/02

https://doi.org/10.1080/00223131.2018.1544939

Times Cited Count：7 Percentile：61.18(Nuclear Science & Technology)

In order to improve LWR source term under severe accident conditions, the first version of a fission product (FP) chemistry database named "ECUME" was developed. The ECUME is intended to include major chemical reactions and their effective kinetic constants for representative SA sequences. It is expected that the ECUME can serve as a fundamental basis from which FP chemical models in the SA analysis codes can be elaborated. The implemented chemical reactions in the first version were those for representative gas species in Cs-I-B-Mo-O-H system. The chemical reaction kinetic constants were evaluated from either literature data or calculated values using ab-initio calculations. The sample chemical reaction calculation using the presently constructed dataset showed meaningful kinetics effects at 1000 K. Comparison of the chemical equilibrium compositions by using the dataset with those by chemical equilibrium calculations has shown rather good consistency for the representative Cs-I-B-Mo-O-H species. From these results, it was concluded that the present dataset should be useful to evaluate FP chemistry in Cs-I-B-Mo-O-H system under LWA SA conditions.

Journal Articles

A Modified version of the analytical potential function for the global ab initio ground-state potential energy surface of the BrH $_{2}$ system

Kurosaki, Yuzuru; Takayanagi, Toshiyuki*

Chemical Physics Letters, 406(1-3), p.121 - 125, 2005/04

https://doi.org/10.1016/j.cplett.2005.02.106

no abstracts in English

Journal Articles

Direct ab initio molecular dynamics study of the two photodissociation channels of formic acid

Kurosaki, Yuzuru; Yokoyama, Keiichi; Teranishi, Yoshiaki

Chemical Physics, 308(3), p.325 - 334, 2005/01

https://doi.org/10.1016/j.chemphys.2004.05.032

Times Cited Count：23 Percentile：60.42(Chemistry, Physical)

A total of 1200 trajectories have been integrated for the two dissociation channels of formic acid, HCOOH H $_{2}$ O + CO (1) and HCOOH CO $_{2}$ + H $_{2}$ (2), which occur with 248 and 193 nm photons, using the direct ab initio molecular dynamics method at the RMP2(full)/cc-pVDZ level of theory. It was found that the percentage of the energy distributed to a relative translational mode in reaction 2 is much larger than that in reaction 1. This is mainly due to the difference in the geometry of transition state (TS); the H $_{2}$ O geometry in the TS of reaction 1 was predicted to significantly deviate from the equilibrium one, whereas the CO $_{2}$ and H $_{2}$ geometries in the TS of reaction 2 were found to be more similar to their equilibrium ones. It was also found that the product diatomic molecules, CO and H $_{2}$ , are both vibrationally and rotationally excited. The calculated relative population of the vibrationally excited CO for the 248 nm photodissociation was consistent with experiment.

Journal Articles

Global potential energy surfaces for the lowest three doublet states (1 $^{2}$ A', 2 $^{2}$ A', and 1 $^{2}$ A") of the BrH $_{2}$ system

Kurosaki, Yuzuru; Takayanagi, Toshiyuki

Journal of Chemical Physics, 119(15), p.7838 - 7856, 2003/10

https://doi.org/10.1063/1.1609398

Times Cited Count：26 Percentile：63.62(Chemistry, Physical)

Adiabatic potential energy surfaces of the lowest three doublet states (1 $^{2}$ A', 2 $^{2}$ A', and 1 $^{2}$ A") for the BrH $_{2}$ system have been calculated globally using the MRCI+Q method with the aug-cc-pVTZ basis set. Spin-orbit effects were considered on the basis of Breit-Pauli Hamiltonian. The calculated adiabatic energies were fitted to the analytical functional form of many-body expansion. The barrier heights of the abstraction and exchange reactions on the ground-state PES were calculated to be 1.28 and 11.71 kcal mol $^{-1}$ , respectively, at the MRCI+Q/aug-cc-pVTZ level of theory. The fits for the three PESs were successful within the accuracy of 0.1 kcal mol $^{-1}$ . Thermal rate constants for the abstraction and exchange reactions and their isotopic variants were calculated with the fitted 1 $^{2}$ A' PES using the ICVT/LAG method. The calculated rate constants for the abstarction reactions agree fairly well with experiment but those for the exchange reactions were much smaller than experiment, which suggests that the reliable experimental data are still insufficient.

JAEA Reports

Environmental construction of nano-material design codes; The Example of simulation codes used in the CMD workshop

Miyazaki, Mikiya*

JAERI-Data/Code 2003-007, 55 Pages, 2003/05

JAERI-Data-Code-2003-007.pdf:2.53MB

Generally it is well known that the R&D works on new materials or devices will play a central role on the evolution of future society. The structure of a substance and material is needed to be dealt with in detail by quantum mechanics, because the limit on accuracy has come in sight in the calculation using a classical theory. The research on the latest electronic state calculation technique founded on quantum mechanics made a great advance as the technique of solving these problems as well as the technique of a computational materials design. It enables the prediction of material properties because it is based on First Principles. Therefore, in the future it is expected to have a very high possibility of becoming a breakthrough in such a situation. In this article, the example calculation results by PC cluster on the codes used in the Computational Materials Design workshop, held on Sep.19-21, at ITBL-Building and IIAS under the auspices of the University of Osaka, are described. Furthermore, the graphical user interfaces on the codes are examined.

Journal Articles

Photodissociation of acetaldehyde, CH $_{3}$ CHOCH $_{3}$ +HCO; Direct ab initio molecular dynamics study

Kurosaki, Yuzuru; Yokoyama, Keiichi

Chemical Physics Letters, 371(5-6), p.568 - 575, 2003/04

https://doi.org/10.1016/S0009-2614(03)00313-0

Times Cited Count：31 Percentile：69.39(Chemistry, Physical)

A total of 400 trajectories for the photodissociation, CH $_{3}$ CHOCH $_{3}$ +HCO, on the T $_{1}$ potential surface have been calculated using the direct ab initio molecular dynamics method at the UB3LYP/cc-pVDZ level of theory. It was predicted that the product CH $_{3}$ is neither vibrationally nor rotationally excited and HCO is vibrationally not excited but rotationally excited. The averaged HCO rotational energy was calculated to be 1.1 kcal/mol, which is 15.1 % of the available energy, 7.3 kcal/mol. The present result agrees with experiment within just a few percent of the observed data.

Journal Articles

study of hydrogen hydrate clathrates for hydrogen storage within the ITBL environment

Sluiter, M. H. F.*; Belosludov, R. V.*; Jain, A.*; Belosludov, V. R.*; Adachi, Hitoshi*; Kawazoe, Yoshiyuki*; Higuchi, Kenji; Otani, Takayuki

Lecture Notes in Computer Science 2858, p.330 - 341, 2003/00

Recently, for the first time a hydrate clathrate was discovered with hydrogen. Aside from the great technological promise that is inherent in storing hydorogen at high density at modest pressures, there is great scientefic interest as this would constitute the first hydrate clathrate with multiple guest molecules per cage. The multiple cage occupancy is controversial, and reproducibility of the experiments has been questioned. Therefore in this study we try to illucidate the remarkable stability of the hydrogen hydrate clathrate, and determine the thermodynamically most favored cage occpancy using highly accrate computer simulations in a parameter survey. To carry out these extraordinary demanding computations a distributed code has been developed using the SuperSINET with the ITBL software as the top-layer.

Journal Articles

Photodissociation of acetaldehyde, CH $_{3}$ CHOCH $_{4}$ +CO: Direct ab initio dynamics study

Kurosaki, Yuzuru; Yokoyama, Keiichi

Journal of Physical Chemistry A, 106(47), p.11415 - 11421, 2002/11

https://doi.org/10.1021/jp020998f

Times Cited Count：36 Percentile：72.97(Chemistry, Physical)

A total of 100 trajectories for the photodissociation, CH $_{3}$ CHO CH $_{4}$ + CO, on the S0 potential surface have been calculated using the direct ab initio molecular dynamics method at the RMP2(full)/cc-pVDZ level of theory. The energy distributions for the relative translational energy, the CO internal energy, and the CH $_{4}$ internal energy were calculated to be 28, 20, and 51 %, respectively. It was predicted that the product CO is highly rotationally excited but vibrationally almost not excited; on average, the rotational and vibrational quantum numbers were 68.2 and 0.15, respectively, which qualitatively agrees with the recent observation of Gherman et al. (J. Chem. Phys. 2001, 114, 6128.)

Journal Articles

Potential energy surface for the C $_{2}$ H $_{4}$ + Cl $_{2}$ C $_{2}$ H $_{4}$ Cl + Cl reaction; Ab initio molecular orbital study

Kurosaki, Yuzuru

Journal of Molecular Structure; THEOCHEM, 545(1-3), p.225 - 232, 2001/07

The CASSCF and MRCI calculations with the cc-pVTZ basis set have been carried out for the C $_{2}$ H $_{4}$ + Cl $_{2}$ C $_{2}$ H $_{4}$ Cl + Cl reaction. It has been revealed that the reaction has a small barrier from the C $_{2}$ H $_{4}$ Cl + Cl side at the CASSCF level of theory, but it has no barrier at the MRCI level. Namely, the C $_{2}$ H $_{4}$ Cl + Cl C $_{2}$ H $_{4}$ + Cl $_{2}$ reaction was predicted to be a spontaneous reaction. The result of the MRCI calculation strongly supports the prediction of our previous PMP4(SDTQ) calculation [J. Mol. Struct. (Theochem) 503 (2000) 231].