Determination of the Ground State Geometries of Copper Clusters by Simulated Annealing

We determine the lowest energy structures of small (10–20 atoms) copper clusters. The semi-empirical Equivalent Crystal Theory (ECT) is used in conjunction with the Metropolis Monte Carlo algorithm to determine the equilibrium geometry of each cluster via simulated annealing. The optimum structures of the clusters in this size range are found to be derived from icosahedral structures. The 13-atom cluster is an icosahedron and the 19-atom one a double-icosahedron. The other sizes show structures related to these. The 10- and 11-atom clusters, however, show somewhat different structures. We report the variation of binding energy, as obtained from ECT, with cluster size.

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DETERMINATION OF THE GROUND-STATE GEOMETRIES OF COPPER CLUSTERS BY SIMULATED ANNEALING WITHIN AN EQUIVALENT CRYSTAL APPROACH

International Journal of Modern Physics B ◽

10.1142/s0217979203015826 ◽

2003 ◽

Vol 17 (03) ◽

pp. 273-279

Author(s):

AMITAVA BANERJEA ◽

RADHIKA PROSAD DATTA ◽

ABHIJIT MOOKERJEE ◽

A. K. BHATTACHARYYA

Keyword(s):

Simulated Annealing ◽

First Principles ◽

Monte Carlo Algorithm ◽

Equilibrium Geometry ◽

Efficient Tool ◽

Copper Clusters ◽

Atom Clusters ◽

Metropolis Monte Carlo ◽

Semi Empirical

We determine the lowest energy structures of small (11–20 atoms) copper clusters. The semi-empirical Equivalent Crystal Theory (ECT) is used in conjunction with the Metropolis Monte Carlo algorithm to determine the equilibrium geometry of each cluster via simulated annealing. The optimum structures of the clusters in this size range are found to be derived from icosahedral structures. The 13-atom cluster is an icosahedron and the 19-atom is a double-icosahedron. The other sizes show structures related to these. The 11-atom clusters, however, show somewhat different structures. We propose the ECT as an efficient tool for developing starting structures for more chemically accurate, first principles and therefore computationally very demanding, approaches.

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A Molecular Full-Potential LMTO Calculation for Copper Clusters

Modern Physics Letters B ◽

10.1142/s0217984997000220 ◽

1997 ◽

Vol 11 (05) ◽

pp. 161-169 ◽

Cited By ~ 1

Author(s):

Radhika Prosad Datta ◽

Amitava Banerjea ◽

Abhijit Mookerjee ◽

A. K. Bhattacharyya

Keyword(s):

Simulated Annealing ◽

Binding Energy ◽

Electronic Properties ◽

Density Of States ◽

Cluster Size ◽

Binding Energies ◽

Full Potential ◽

Copper Clusters ◽

Total Energies ◽

Homo Lumo

We study the electronic properties of small (10–20 atoms) copper clusters using the newly-developed molecular full-potential linearized muffin-tin orbital two-centre-fit (TCF) method of Methfessel and van Schilfgaarde. The geometric structures of the clusters had earlier been determined by us through simulated annealing using the Equivalent Crystal Theory to compute total energies. We report the variation of the binding energy, as obtained from the TCF calculations, with cluster size and compare these to the binding energies determined, for the same structures, from the ECT. We also show the variation of the HOMO-LUMO gap with cluster size, and the pseudo-density of states for select cluster sizes.

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FINITE-TEMPERATURE SIMULATION OF ABSORPTION SPECTRA IN SMALL ARGON-CLUSTER IONS ${\rm Ar}_n^ + $(n=3, 4, 8, 13, AND 19)

Surface Review and Letters ◽

10.1142/s0218625x96000425 ◽

1996 ◽

Vol 03 (01) ◽

pp. 211-215 ◽

Cited By ~ 24

Author(s):

M. GRIGOROV ◽

F. SPIEGELMANN

Keyword(s):

Absorption Spectra ◽

Finite Temperature ◽

Potential Energy Surfaces ◽

Monte Carlo Algorithm ◽

Cluster Ions ◽

Nuclear Motion ◽

Spin Orbit Coupling ◽

Metropolis Monte Carlo ◽

Energy Surfaces

We report finite-temperature simulations of the absorption spectra of argon-cluster ions using a diatomics in molecules (DIM) Hamiltonian (including spin-orbit coupling) for the determination of the potential-energy surfaces (PES), a point-charge approximation for the dipole transition moments and a Metropolis Monte-Carlo algorithm for the nuclear motion. The dependency of the absorption spectrum on cluster size (3≤n≤19) and on temperature (100 K≤T≤500 K) is analyzed.

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Determination of effective atomic numbers for 3d transition metal alloys with a new semi-empirical approach

Annals of Nuclear Energy ◽

10.1016/j.anucene.2011.09.008 ◽

2012 ◽

Vol 39 (1) ◽

pp. 56-61 ◽

Cited By ~ 25

Author(s):

I. Han ◽

M. Aygun ◽

L. Demir ◽

Y. Sahin

Keyword(s):

Transition Metal ◽

Empirical Approach ◽

Metal Alloys ◽

Transition Metal Alloys ◽

Effective Atomic Numbers ◽

Semi Empirical

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Computational determination of equilibrium geometry and dissociation energy of the water dimer

Physical Chemistry Chemical Physics ◽

10.1039/a910312k ◽

2000 ◽

Vol 2 (10) ◽

pp. 2227-2234 ◽

Cited By ~ 199

Author(s):

W. Klopper ◽

J. G. C. M. van Duijneveldt-van de Rijdt ◽

F. B. van Duijneveldt

Keyword(s):

Dissociation Energy ◽

Water Dimer ◽

Equilibrium Geometry

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Determination of the Effective Depth for Double-Fiber Fluorometric Sensors

Applied Spectroscopy ◽

10.1366/0003702924124358 ◽

1992 ◽

Vol 46 (6) ◽

pp. 919-924 ◽

Cited By ~ 12

Author(s):

Zhong Yuan Zhu ◽

M. Cecilia Yappert

Keyword(s):

Fiber Optic Sensor ◽

Fluorescence Signal ◽

Acceptance Angle ◽

Fiber Sensors ◽

Sample Depth ◽

Effective Depth ◽

Different Diameters ◽

Semi Empirical ◽

Analytical Expressions

The relationship between the relative fluorescence signal excited and collected with a double-fiber optic sensor and the sample depth has been investigated. The complexity of the analytical expressions for the relative fluorescence signal and the effective depth was reduced by deriving a set of semi-empirical equations which can be evaluated in a simple fashion. These expressions take into account the configuration of the sensor, i.e., fiber diameter, acceptance angle, and separation between fibers. The expressions were tested with the use of double-fiber sensors with different diameters and separations between fibers. The reduction of the effective depth in solutions with significant absorbance was evaluated.

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Determination of the three-dimensional solution structure of the antihypertensive and antiviral protein BDS-I from the sea anemone Anemonia sulcata: a study using nuclear magnetic resonance and hybrid distance geometry-dynamical simulated annealing

Biochemistry ◽

10.1021/bi00431a033 ◽

1989 ◽

Vol 28 (5) ◽

pp. 2188-2198 ◽

Cited By ~ 107

Author(s):

Paul C. Driscoll ◽

Angela M. Gronenborn ◽

Laszlo Beress ◽

G. Marius Clore

Keyword(s):

Nuclear Magnetic Resonance ◽

Simulated Annealing ◽

Solution Structure ◽

Distance Geometry ◽

Three Dimensional ◽

Antiviral Protein ◽

Dimensional Solution ◽

Anemonia Sulcata ◽

Hybrid Distance

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A New Approach for Erosion Prediction Due To Fly Ash

Journal of Engineering for Power ◽

10.1115/1.3230716 ◽

1981 ◽

Vol 103 (2) ◽

pp. 265-270 ◽

Cited By ~ 14

Author(s):

R. Kotwal ◽

W. Tabakoff

Keyword(s):

Fly Ash ◽

Gas Turbines ◽

Precise Determination ◽

Erosion Prediction ◽

Industrial Gas Turbines ◽

Series Of Experiments ◽

A New Technique ◽

Nickel Base ◽

Semi Empirical

With increasing interest in the burning of coal in industrial gas turbines, there is also concern for the precise determination of the erosive effects on the turbine components. Series of experiments were conducted to determine the effects of fly ash constituents, particle size, particle velocity, angle of attack and target temperature on the erosion of iron and nickel base alloys. Based on the experimental results, a semi-empirical equation has been obtained for the prediction of the erosion losses. This equation provides a new technique for predicting the metal erosion due to the fly ash produced by the conventional burning of coal.

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