Scopus İndeksli Yayınlar Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12416/8651
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Article Citation - WoS: 3Citation - Scopus: 3Dissociative Chemisorption of an H2 (V,j) Molecule on Rigid Ni (100) Surface: Dependence on Surface Topologies and Initial Rovibrational States of the Molecules(Iop Publishing Ltd, 2005) Evecen, M; Böyükata, M; Çivi, M; Güvenç, ZBThe H-2(v,j)+Ni(100) collision system has been studied to understand the effects of the surface sites and initial rovibrational states of the molecule on molecule-surface interactions, by a quasiclassical molecular dynamic simulation method. Dissociative adsorption of an H-2 molecule on the rigid Ni(100) surface is investigated at topologically different three sites of the surface. Interaction between the molecule and Ni surface was described by a London-Eyring Polani-Sato (LEPS) potential. Dissociative chemisorption probabilities of the H-2(v, j) molecule on various sites of the surface are presented as a function of the translation energies between 0.001-1.0eV. The probabilities obtained at each collision site have unique behaviour. At lower collision energies, indirect processes enhance the reactivity, effects of the rotational excitations and impact sites on the reactivity are more pronounced. The results are compared with the available studies, The physical mechanisms underlying the results and quantum effects are discussed.Article Citation - WoS: 3Citation - Scopus: 3Collisionless Fragmentation of Non-Rotating Nin (n=4-14) Clusters: a Molecular Dynamics Study(Iop Publishing Ltd, 2003) Avci, H; Çivi, M; Güvenç, ZB; Jellinek, JCollisionless fragmentation of non-rotating Ni-n (n = 4-14) clusters is studied using micro-canonical molecular dynamics (MD) computer simulations. The clusters are modelled by an embedded-atom potential energy surface. The distributions of the channel-specific fragmentation probabilities, and the global and channel-specific fragmentation rate constants are computed and analysed as functions of the internal energy and size of the clusters. The trends derived from the dynamical calculations are compared to the fragmentation energy patterns, those of the Rice-Ramsperger-Kassel (RRK) and statistical approaches. The rate constants are an order of magnitude smaller for the RRK model than with both the MD and transition-state theory approaches. The results are also compared with the other multi-channel fragmentation works.Article Citation - WoS: 49Citation - Scopus: 49Global Minima of Aln, Aun and Ptn, N≤80, Clusters Described by the Voter-Chen Version of Embedded-Atom Potentials(Iop Publishing Ltd, 2005) Sebetci, A; Güvenç, ZBWe report the global minima for aluminium, gold and platinum metal clusters modelled by the Voter-Chen version of the embedded-atom model potential containing up to 80 atoms using the basin-hopping Monte Carlo minimization approach. The results show that the global minima of the Al, Au and Pt clusters have structures based on either octahedral, decahedral, icosahedral or a mixture of decahedral and icosahedral packing. The 54-atom icosahedron without a central atom is found to be more stable than the 55-atom complete icosahedron for all of the elements considered in this work. Most of the Al global minima are identified as face-centred cubic structures and many of the An global minima are found to be low symmetric structures, both of which are in agreement with the previous theoretical and experimental Studies. Although many of the Pt global minima are identical with the global minima of the corresponding Au clusters, the most stable sizes of the Pt clusters correspond to the same sizes of the Al clusters.Article Citation - WoS: 9Citation - Scopus: 10Structures and Melting of Agn (N = 7, 12-14) Clusters(Iop Publishing Ltd, 2005) Atis, M; Aktas, H; Güvenç, ZBWe have studied the most stable structures of Ag-N (N = 7, 12, 13, 14) clusters and investigated their binding energies and melting behaviours using molecular dynamics and thermal quenching methods based on the Voter-Chen version of the embedded atom method. The melting like transition is described in terms of atom resolved root-mean-square bond length fluctuations, specific heats, coordination numbers and short-time averaged temperatures. Some of these diagnostic tools are also used for the overall behaviour of the clusters. The results are compared with the relevant literature.