MOLECULAR-DYNAMICS SIMULATIONS OF NICKEL CLUSTERS

2000 ◽  
Vol 11 (05) ◽  
pp. 1013-1024 ◽  
Author(s):  
ŞAKIR ERKOÇ ◽  
BILAL GÜNEŞ ◽  
PERVIN GÜNEŞ

Structural stability and energetics of nickel clusters, NiN (N =3-459), have been investigated by molecular-dynamics simulations. A size-dependent empirical model potential energy function has been used in the simulations. Stable structures of the microclusters with sizes N = 3-55 and clusters generated from fcc crystal structure with sizes N = 79-459 have been determined by molecular-dynamics simulations. It has been found that the five-fold symmetry appears on the surface of the spherical clusters. The average coordination number shows a size-dependent characteristic, on the other hand the average nearest-neighbor distance does not show a size-dependence.

2000 ◽  
Vol 11 (08) ◽  
pp. 1567-1580 ◽  
Author(s):  
BILAL GÜNEŞ ◽  
ŞAKIR ERKOÇ

Melting and fragmentation behaviors of Ni 429 cluster have been studied with molecular-dynamics simulations using a size-dependent empirical model potential energy function. To monitor thermal behaviors of the cluster, we calculated some physical quantities such as average potential energy per atom, specific heat, radial atomic distribution, bond length distribution, average interatomic distance, nearest neighbor distance and average coordination number as a function of temperature. The roles of the surface and core atoms in the melting and fragmentation process of the cluster are also investigated by considering the surface and the bulk coordination numbers of the cluster.


2005 ◽  
Vol 502 ◽  
pp. 51-56 ◽  
Author(s):  
Sakir Erkoc

The structural and electronic properties of isolated neutral ZnmCdn clusters for m+n £ 3 have been investigated by performing density functional theory calculations at B3LYP level. The optimum geometries, vibrational frequencies, electronic structures, and the possible dissosiation channels of the clusters considered have been obtained. An empirical many-body potential energy function (PEF), which comprices two- and three-body atomic interactions, has been developed to investigate the structural features and energetics of ZnmCdn (m+n=3,4) microclusters. The most stable structures were found to be triangular for the three-atom clusters and tetrahedral for the four-atom clusters. On the other hand, the structural features and energetics of Znn-mCdm (n=7,8) microclusters, and Zn50, Cd50, Zn25Cd25, Zn12Cd38, and Zn38Cd12 nanoparticles have been investigated by performing molecular-dynamics computer simulations using the developed PEF. The most stable structures were found to be compact and three-dimensional for all elemental and mixed clusters. An interesting structural feature of the mixed clusters is that Zn and Cd atoms do not mix in mixed clusters, they come together almost without mixing. Surface and bulk properties of Zn, Cd, and ZnCd systems have been investigated too by performing molecular-dynamics simulations using the developed PEF. Surface reconstruction and multilayer relaxation on clean surfaces, adatom on surface, substitutional atom on surface and bulk materials, and vacancy on surface and bulk materials have been studied extensively.


2009 ◽  
Vol 60-61 ◽  
pp. 315-319 ◽  
Author(s):  
W.W. Zhang ◽  
Qing An Huang ◽  
H. Yu ◽  
L.B. Lu

Molecular dynamics simulations are carried out to characterize the mechanical properties of [001] and [110] oriented silicon nanowires, with the thickness ranging from 1.05nm to 3.24 nm. The nanowires are taken to have ideal surfaces and (2×1) reconstructed surfaces, respectively. A series of simulations for square cross-section Si nanowires have been performed and Young’s modulus is calculated from energy–strain relationship. The results show that the elasticity of Si nanowires is strongly depended on size and surface reconstruction. Furthermore, the physical origin of above results is analyzed, consistent with the bond loss and saturation concept. The results obtained from the molecular dynamics simulations are in good agreement with the values of first-principles. The molecular dynamics simulations combine the accuracy and efficiency.


2005 ◽  
Vol 1 (4) ◽  
pp. 204-209
Author(s):  
O.B. Malcıoğlu ◽  
Ş. Erkoç

The minimum energy structures of CmTin microclusters and nanoparticles have been investigated theoretically by performing molecular–dynamics (MD) simulations. Selected crystalline and completely random initial geometries are considered. The potential energy function (PEF) used in the calculations includes two– and three–body atomic interactions for C-Ti binary systems. Molecular–dynamics simulations have been performed at 1 K and 300 K. It has been found that initial geometry has a very strong influence on relaxed geometry


2019 ◽  
Vol 21 (19) ◽  
pp. 9865-9875 ◽  
Author(s):  
Sharmin Shabnam ◽  
Qian Mao ◽  
Adri C. T. van Duin ◽  
K. H. Luo

Effect of nickel clusters on the formation of incipient soot from PAH precursors via ReaxFF-MD simulations.


2012 ◽  
Vol 1407 ◽  
Author(s):  
Andrew L. J. Pang ◽  
Viacheslav Sorkin ◽  
Yong-Wei Zhang

ABSTRACTWe studied the self-assembly mechanisms of Graphene Nanoribbon (GNR) with unsaturated edges and demonstrated the ability of GNR to self-assemble into novel stable structures. We proposed three mechanisms which dictate the self-assembly evolution of GNR with unsaturated edges. Using the Adaptive Intermolecular Reactive Empirical Bond-Order (AIREBO) potential, we performed molecular dynamics simulations on initially-planar GNRs with unsaturated edges. The simulation results showed that the self-assembly mechanisms and final conformations of the GNRs correlate well with the proposed GNR self-assembly mechanisms. Furthermore, the simulations also showed the ability of a narrow GNR to self-assemble into various nanostructures, such as tapered graphene nano-rings and graphene nanoscrolls with an embedded nanotube.


2004 ◽  
Vol 15 (06) ◽  
pp. 917-930 ◽  
Author(s):  
ZUHEIR EL-BAYYARI ◽  
HÜSEYIN OYMAK ◽  
HATICE KÖKTEN

Using an empirical potential energy function parametrized for each of the Ni , Cu , Pd , Pt , and Pb systems, minimum-energy structures of Ni n, Cu n, Pd n, Pt n, and Pb n (n=3–13) microclusters have been determined by performing molecular-dynamics simulations. The structural and energetic features of the obtained microclusters have been investigated.


1990 ◽  
Vol 206 ◽  
Author(s):  
R.C. Mowrey ◽  
D.W. Brenner ◽  
B.I. Dunlap ◽  
J.W. Mintmire ◽  
C.T. White

ABSTRACTWe have performed molecular dynamics simulations using a recently developed empirical many-body potential energy function to study the collision of the C60 isomer buckmin-sterfullerene with a hydrogen-terminated diamond surface. The simulations indicate that the cluster can react with the surface and has a larger probability of gaining atoms from the surface than of losing atoms to the surface. We have investigated the dependence of the reaction probability on the initial center-of-mass translational velocity of the cluster. The structures and energy distributions of the product clusters have been determined. Both inelastically and reactively scattered clusters have large amounts of internal energy which suggests that gas-phase dissociation is likely.


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