Elektronik ve Haberleşme Mühendisliği Bölümü

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Citation - WoS: 46
Citation - Scopus: 47
Density Functional Study of Albn Clusters for N=1-14
(Elsevier Science Sa, 2011) Boyukata, Mustafa; Guvenc, Ziya B.
Density functional theory (DFT) B3LYP at 6-311++G(d,p) level is employed to optimize the structures of AlBn (n = 1-14) microclusters. Analysis of the energetic and structural stability of these clusters and their various isomers are presented. Total and binding energies of the clusters have been calculated. Their harmonic frequencies, point symmetries, and the highest occupied molecular orbital-lowest unoccupied molecular orbital (HOMO-LUMO) energy gaps have been determined. Results are evaluated by comparing to the previous similar works. (C) 2011 Elsevier B.V. All rights reserved.
Citation - WoS: 32
Density Functional Study of Physical and Chemical Properties of Nano Size Boron Clusters: Bn (n=13-20)
(Chinese Physical Soc, 2009) Ozdogan, Cem; Guvenc, Ziya B.; Atis, Murat
Boron is an element that has ability to build strong and highly directional bonds with boron itself. As a result, boron atoms form diverse structural motifs, ultimately can yield distinct nano structures, such as planar, quasi-planar, convex, cage, open-cage, tubular, spherical., ring, dome-like, shell, capsule, and so on, i.e., it can take almost any shape. Therefore, a deep understanding of the physical and chemical properties becomes important in boron cluster chemistry. Electronic and geometric structures, total and binding energies, harmonic frequencies, point symmetries, charge distributions, dipole moments, chemical bondings and the highest occupied molecular orbital-lowest unoccupied molecular orbital energy gaps of neutral B-n (n=13-20) clusters have been investigated by, density functional theory (DFT), B3LYP with 6-311++G(d,p) basis set. Furthermore, the first and the second energy differences are used to obtain the most stable sizes. We have observed that almost all physical properties are size dependent, and double-ring tubular form of B-20 has the highest binding energy per atom. The icosahedral structure with an inside atom is found as impossible as a stable structure for the size thirteen. This structure transforms to an open-cage form. The structural transition from two-dimensional to three-dimensional is found at the size of 20 and consistent with the literature. The calculated charges by the Mulliken analysis show that there is a symmetry pattern with respect to the x-z and y-z planes for the charge distributions. The unusual planar stability of the boron clusters may be explained by the delocalized pi and sigma bonding characteristic together with the existence of the multicentered bonding. The results have been compared to available studies in the literature.
Citation - WoS: 13
Dft Study of Al Doped Cage B12hn Clusters
(Pergamon-elsevier Science Ltd, 2011) Boyukata, Mustafa; Guvenc, Ziya B.
Density Functional Theory (DFT) with B3LYP/6-311++g** level has been performed to investigate the electronic structures of cage B12Hn for up to n <= 12 and AlB12Hn for up to n <= 13. Moreover, the computations has been extended to the charged clusters of [B12H12](q), [AlB12H12](q) and [AlB12H13](q) where (q = +/- 1 and +/- 2). Their energetics are calculated and structural analysis have been carried out. Cage form of the B-12 remains stable against to hydrogen adsorptions. Copyright (C) 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.
Citation - WoS: 53
Citation - Scopus: 61
Structure and Energetic of Bn (n=2-12) Clusters: Electronic Structure Calculations
(Wiley, 2007) Oezdogan, Cem; Guevenc, Ziya B.; Atis, Murat
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.

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