Browsing by Author "Guevenc, Ziya B."

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Citation - WoS: 1
Citation - Scopus: 1
Determination of chemisorption probabilities of hydrogen molecules on a nickel surface by Artificial Neural Network
(Croatian Chemical Soc, 2008) Boeyuekata, Mustafa; Kocyigit, Yuecel; Guevenc, Ziya B.; 120207; 53469
Dissociative chemisorption probabilities for H-2(v, j) + Ni(100) collision systems have been estimated by using Artificial Neural Network (ANN). For training, previously determined probability values via molecular dynamics simulations have been used. Performance of the ANN, for predicting any quantities in the molecule-surface interaction, has been investigated. Effects of the surface sites and the rovibrational states of the molecule on the process are analyzed. The results are in good agreement with the related previous studies.
Citation - WoS: 4
Citation - Scopus: 3
Developing interaction potential for H (2H) -> Cu(111) interaction system: A numerical study
(Elsevier Science Bv, 2010) Vurdu, Can D.; Guevenc, Ziya B.
In this study, we have used London-Eyring-Polanyi-Sato (LEPS) functional form as an interaction potential energy function to simulate H (2H) -> Cu(1 1 1) interaction system The parameters of the LEPS function are determined in order to analyze reaction dynamics via molecular dynamics computer simulations of the Cu(1 1 1) surface and H/(2H) system. Nonlinear least-squares method is used to find the LEPS parameters. For this purpose, we use the energy points which were calculated by a density-functional theory method with the generalized gradient approximation including exchange-correlation energy for various configurations of one and two hydrogen atoms on the Cu(1 1 1) surface. After the fitting procedures, two different parameters sets are obtained that the calculated root-mean-square values are close to each other. Using these sets, contour plots of the potential energy surfaces are analyzed for H -> Cu(1 1 1) and 2H -> Cu(1 1 1) interactions systems. In addition. sticking, penetration, and scattering sites on the surface are analyzed by using these sets. (C) 2009 Elsevier B.V. All rights reserved.
Citation - WoS: 52
Citation - Scopus: 59
Structure and energetic of Bn (n 2–12) clusters: electronic structure calculations
(Wiley, 2007) Atis, Murat; Özdoğan, Cem; Oezdogan, Cem; Guevenc, Ziya B.; Ortak Dersler Bölümü
The electronic and geometric structures, total and binding energies, first and second energy differences, harmonic frequencies, point symmetries, and highest occupied molecular orbital-lowest unoccupied molecular orbital (HOMO-LUMO) gaps of small and neutral B-n (n = 2-12) clusters have been investigated using density functional theory (DFT), B3LYP with 6-311 + + G(d,p) basis set. Linear, planar, convex, quasi-planar, three-dimensional (3D) cage, and open-cage structures have been found. None of the lowest energy structures and their isomers has an inner atom; i.e., all the atoms are positioned at the surface. Within this size range, the planar and quasi-planar (convex) structures have the lowest energies. The first and the second energy differences are used to obtain the most stable sizes. A simple growth path is also discussed with the studied sizes and isomers. The results have been compared with previously available theoretical and experimental works. (C) 2006 Wiley Periodicals, Inc.