STRUCTURAL AND DYNAMICAL PROPERTIES IN LIQUID Ni AND Ag BY COMPUTER SIMULATION

2003 ◽  
Vol 17 (07) ◽  
pp. 1011-1025 ◽  
Author(s):  
EFRAÍN URRUTIA-BAÑUELOS ◽  
ALVARO POSADA-AMARILLAS
Keyword(s):  
Tight Binding ◽  
Interatomic Interaction ◽  
Experimental Information ◽  
Simple Liquid ◽  
Common Neighbor ◽  
Moment Approximation ◽  
Liquid Behavior ◽  
Dynamical Properties ◽  
Body Potential ◽  
Theoretical Results

We studied the temperature dependence of the structural and dynamical properties for liquid nickel and silver by modeling the interatomic interaction through a tight-binding n-body potential in the second-moment approximation (TB-SMA). A common-neighbor analysis was performed to explore the microstructural changes with temperature in Ni and Ag in the liquid state in terms of their inherent structures (IS). A tendency to the formation of more symmetric IS characteristic of the BCC crystalline and icosahedral order is observed as the temperature is raised. At the same time, the FCC and HCP crystalline order is reduced while the BCC-type order increases. The simulated diffusion coefficients are in reasonable agreement with the available experimental information and with other theoretical results. The simple liquid behavior is shown by an Arrhenius plot for both nickel and silver.

scholarly journals Magnetic and vibrational properties of small chromium clusters on the Cu(111) surface

2021 ◽  
Author(s):  
S. D. Borisova ◽  
S. V. Eremeev ◽  
G. G. Rusina ◽  
E. V. Chulkov
Keyword(s):  
Magnetic Properties ◽  
Tight Binding ◽  
Interatomic Interaction ◽  
Vibrational Properties ◽  
Dft Theory ◽  
Interaction Potentials ◽  
Second Moment ◽  
Moment Approximation

The structure and magnetic properties of small Cr clusters adsorbed on the Cu(111) surface have been investigated using DFT theory and their vibrational properties have been calculated using tight-binding second moment approximation interatomic interaction potentials.

A new many-body potential with the second-moment approximation of tight-binding scheme for Hafnium

2013 ◽  
Vol 56 (11) ◽  
pp. 2071-2080
Author(s):  
DeYe Lin ◽  
Yi Wang ◽  
ShunLi Shang ◽  
ZhaoPing Lu ◽  
ZiKui Liu ◽  
...  
Keyword(s):  
Tight Binding ◽  
Many Body ◽  
Second Moment ◽  
Moment Approximation ◽  
Body Potential

Molecular-Dynamics Study of the Morphological Evolution of a Metallic Cluster Deposited on a Surface

2006 ◽  
Vol 924 ◽  
Author(s):  
Kazuhito Shintani ◽  
K. Terajima ◽  
Y. Kometani
Keyword(s):  
Molecular Dynamics ◽  
Morphological Evolution ◽  
Tight Binding ◽  
Dynamics Simulation ◽  
Many Body ◽  
Total Period ◽  
Cu Substrate ◽  
Moment Approximation ◽  
The Many ◽  
Body Potential

ABSTRACTThe morphological evolution of a Co cluster deposited on a Cu substrate is investigated by means of molecular-dynamics simulation. The many-body potential based on the second moment approximation of a tight-binding Hamiltonian (TB-SMA) is employed to calculate the interactions between Co and Cu atoms. The results show that the effect of the substrate anisotropy appears in the morphology of a deposited cluster. It is also revealed that the total period of the structural change of such a cluster can be divided into the three stages, viz., (I)change to an epitaxial structure, (II)overspread of diffusing Cu atoms on the cluster, and (III)solid dissolution of Co atoms into the Cu substrate.

More Dynamical Properties Revealed from a 3D Lorenz-like System

2014 ◽  
Vol 24 (10) ◽  
pp. 1450133 ◽  
Author(s):  
Haijun Wang ◽  
Xianyi Li
Keyword(s):  
Numerical Simulations ◽  
Local Stability ◽  
Equilibrium Points ◽  
Heteroclinic Orbits ◽  
Mathematical Work ◽  
Chaotic Attractors ◽  
Heteroclinic Cycles ◽  
Homoclinic And Heteroclinic Orbits ◽  
Dynamical Properties ◽  
Theoretical Results

After a 3D Lorenz-like system has been revisited, more rich hidden dynamics that was not found previously is clearly revealed. Some more precise mathematical work, such as for the complete distribution and the local stability and bifurcation of its equilibrium points, the existence of singularly degenerate heteroclinic cycles as well as homoclinic and heteroclinic orbits, and the dynamics at infinity, is carried out in this paper. In particular, another possible new mechanism behind the creation of chaotic attractors is presented. Based on this mechanism, some different structure types of chaotic attractors are numerically found in the case of small b > 0. All theoretical results obtained are further illustrated by numerical simulations. What we formulate in this paper is to not only show those dynamical properties hiding in this system, but also (more mainly) present a kind of way and means — both "locally" and "globally" and both "finitely" and "infinitely" — to comprehensively explore a given system.

scholarly journals The role of taking into account the interatomic interaction in predicting the complex of structurally-sensitive properties of steels and alloys for special purpose

2018 ◽  
pp. 361-370
Author(s):  
I.R. Snihura ◽  
D.N. Togobitskaya
Keyword(s):  
Computational Models ◽  
State Parameter ◽  
Interatomic Interaction ◽  
Homogeneous System ◽  
Experimental Information ◽  
Structure Property ◽  
Chain Composition ◽  
Forecast Models ◽  
Composition Structure

The aim of the work is to identify the influence of the chemical composition of steels and special-purpose alloys on the formation of their physicochemical and structural-sensitive properties. This problem is solved by mathematical modeling of the inseparable chain «composition - structure – property» taking into account the parameters of interatomic interaction in the melt based on the concept of a directed chemical bond. A steel melt is considered as a chemically homogeneous system, and the state of the melts is expressed through a set of integral parameters, the main of which are: Zy - system charge state parameter (e); r - statistically average internuclear distance (10-1nm); tgα is a constant for each element, which characterizes the change in the radius of the ion as its charge changes. On the basis of experimental information on properties and using the parameters of interatomic interaction, computational models are proposed for predicting the properties of steels and alloys. The forecast models took into account the parameters of micro-inhomogeneity of steel, which ensured a high accuracy of the operational forecast. A comparative analysis of the results of steel melting with the corresponding calculations based on the JMatPro software package confirmed the effectiveness of using the interatomic interaction parameters as models. The proposed models for determining the melting of chromium-nickel steels are recommended for use with the content of basic elements Cr, Ni from 0 to 30%. The research results are recommended for use in industrial environments through the integration of the developed models in the process control system of steelmaking, which will contribute to the directed formation of the composition and properties of smelting products, as well as reducing energy costs.

GLOBAL MINIMA FOR PdN (N = 5–80) CLUSTERS DESCRIBED BY SUTTON–CHEN POTENTIAL

2007 ◽  
Vol 18 (08) ◽  
pp. 1351-1359 ◽  
Author(s):  
HAYDAR ARSLAN
Keyword(s):  
Monte Carlo ◽  
Energy Surface ◽  
Central Atom ◽  
Low Energy ◽  
Global Minima ◽  
Many Body ◽  
Pd Clusters ◽  
Body Potential ◽  
Basin Hopping ◽  
Theoretical Results

The structure and energetics of Pd N (N = 5–80) clusters have been studied extensively by a Monte Carlo method based on Sutton–Chen many-body potential. The basin-hopping algorithm is used to find the low-energy minima on the potential energy surface for each nuclearity. A variety of structure types (icosahedral, decahedral and fcc closed-packed) are observed for Pd clusters. Some of the icosahedral global minima do not have a central atom. The resulting structures have been compared with the previous theoretical results.

scholarly journals Global Dynamics of Some Exponential Type Systems

2020 ◽  
Vol 2020 ◽  
pp. 1-24
Author(s):  
A. Q. Khan ◽  
H. M. Arshad ◽  
B. A. Younis ◽  
KH. I. Osman ◽  
Tarek F. Ibrahim ◽  
...  
Keyword(s):  
Fixed Point ◽  
Lyapunov Function ◽  
Exponential Type ◽  
Type Systems ◽  
Global Dynamics ◽  
Dynamical Properties ◽  
Boundedness And Persistence ◽  
Invariant Rectangle ◽  
Theoretical Results ◽  
Positive Fixed Point

We explore the boundedness and persistence, existence of an invariant rectangle, local dynamical properties about the unique positive fixed point, global dynamics by the discrete-time Lyapunov function, and the rate of convergence of some 2,3-type exponential systems of difference equations. Finally, theoretical results are numerically verified.

ISOMERS OF COPPER CLUSTERS OBTAINED BY A MOLECULAR DYNAMICS MODEL

2005 ◽  
Vol 19 (15n17) ◽  
pp. 2359-2364
Author(s):  
LING WANG ◽  
XI-JING NING
Keyword(s):  
Molecular Dynamics ◽  
Tight Binding ◽  
Magic Number ◽  
Tight Binding Model ◽  
Dynamics Model ◽  
Binding Model ◽  
Higher Symmetry ◽  
Empirical Potential ◽  
Copper Clusters ◽  
Moment Approximation

A molecular dynamics model was developed to search for stable copper clusters with up to 60 atoms by Gupts empirical potential based on the second-moment approximation to tight-binding model (TB-SMA). We found that isomers do not emerge until the clusters have more than 7 atoms, getting more for clusters with 30~52 atoms, and the magic number, 13, 19, 23, 26, 28, 32, 38, 43, 46, 49, and 55 have ground clusters with higher symmetry and have few isomers.

Structural and Electronic Properties of a-Gaas: A Tight-Binding–Molecular-Dynamics–Art Simulation

1997 ◽  
Vol 491 ◽  
Author(s):  
Laurent J. Lewis ◽  
Normand Mousseau
Keyword(s):  
Molecular Dynamics ◽  
Mechanical Model ◽  
Tight Binding ◽  
Structural Models ◽  
Type Model ◽  
Low Density ◽  
Needed Information ◽  
Structural And Electronic Properties ◽  
Dynamical Properties ◽  
Tetrahedral Semiconductors

ABSTRACTBy combining tight-binding (TB) molecular dynamics (MD) with the recently-proposed activation-relaxation technique (ART), we have constructed structural models of a-GaAs and a-Si of an unprecedented level of quality: the models are almost perfectly four-fold coordinated and, in the case of a-GaAs, exhibit a remarkably low density of homopolar bonds. In particular, the models are superior to structures obtained using melt-and-quench TB-MD or quantum MD. We find that a-Si is best described by a Polk-type model, while a-GaAs resembles closely the mechanical model proposed by Connell and Temkin, which is free of wrong bonds. In this paper, the structural, electronic, and dynamical properties of a-GaAs based on this approach will be reviewed, and compared to experiment and other structural models. Our study provides much-needed information on the intermediate-range topology of amorphous tetrahedral semiconductors; in particular, we will see that the differences between the Polk and Connell-Temkin models, while real, are difficult to extract from experiment, thus emphasising the need for realistic computer models.

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