Ground-state correlations and linear response of metal clusters

1995 ◽  
Vol 51 (7) ◽  
pp. 4569-4578 ◽  
Author(s):  
C. Yannouleas ◽  
F. Catara ◽  
N. Van Giai
Keyword(s):  
Ground State ◽  
Linear Response ◽  
Metal Clusters

Determination of Transitional Size of Metal Clusters

2013 ◽  
Author(s):  
Y. H. Park ◽  
I. Hijazi
Keyword(s):  
Monte Carlo ◽  
Size Effect ◽  
Ground State ◽  
Global Minimum ◽  
Metal Clusters ◽  
Critical Size ◽  
Empirical Method ◽  
Ground State Structure ◽  
State Structure ◽  
Eam Potential

We investigated the transitional size of metal clusters where the electronic effect and the size effect on the ground state structure become weaker. Identification of a transitional size cluster provides the means to efficiently determine the ground state structure of large clusters using density functional theory. Beyond the critical size of clusters, geometrical effects become important and the putative global minimum obtained from an empirical method can be used to determine the true ground state structure where the size effect on structures is less significant. We identified the lowest-energy structure using a first principles method in combination with the global search algorithm. We then used the similarity function to quantify structural difference and similarity between the global minimum obtained from an empirical method and the true ground state structure. Two structures become similar beyond a certain critical size. To investigate low-lying structures of metal clusters, we used a Monte Carlo simulated annealing method which employs the Aggregate-Volume-Bias Monte Carlo (AVBMC) algorithm. Incorporated in the Monte Carlo method is an Embedded Atom Method (EAM) potential developed by the authors.

scholarly journals Quantum-Chemical Design of Molecular Structures of Tetra-, Penta- and Hexanuclear Metal Clusters Containing Aluminum and 3d-Element Atoms

Materials ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1852
Author(s):  
Oleg V. Mikhailov ◽  
Denis V. Chachkov
Keyword(s):  
Ground State ◽  
Quantum Chemical ◽  
Metal Clusters ◽  
Complex Dynamics ◽  
Thermodynamic Characteristics ◽  
Molecular Structures ◽  
Spin Multiplicity ◽  
Structural Isomers ◽  
The Individual ◽  
The Given

Various data on the structural and thermodynamic characteristics of polynuclear metal clusters containing atoms of aluminum and various d-elements with the general formula AlnMm where (n + m) is 4, 5, or 6, and which can be precursors for the formation of nanoparticles of elemental metals or intermetallic compounds, have been systematized and discussed. It has been noted that each of these metal clusters in principle is able to exist in very diverse structural isomers, differing significantly among themselves in terms of the total energy and spin multiplicity of the ground state, the number of which is determined by both the specific values of n and m, and the nature of d-elements in their compositions. The presence of very complex dynamics with respect to the changes of the individual thermodynamic characteristics of the metal clusters under consideration as well as the thermodynamic parameters of the reactions of their formation, depending on the nature of the d-element, were also ascertained. In the main, the given review is devoted to the authors’ works published over the last 10 years. Bibliography – 96 references.

MAGNETISM OF SMALL TRANSITION-METAL CLUSTERS AND EFFECTS OF ISOMERIZATION

1996 ◽  
Vol 03 (01) ◽  
pp. 463-466 ◽  
Author(s):  
PETER BORRMANN ◽  
BERND DIEKMANN ◽  
EBERHARD R. HILF ◽  
DAVID TOMÁNEK
Keyword(s):  
Magnetic Properties ◽  
Transition Metal ◽  
Ground State ◽  
Density Functional ◽  
Input Data ◽  
Metal Clusters ◽  
Magnetic Behavior ◽  
Computational Effort ◽  
Transition Metal Clusters ◽  
Ground State Energies

We investigate the magnetic properties of small transition-metal clusters using a simple statistical model, which requires some input data from ab-initio spin-density-functional calculations. In our study, we consider a thermodynamically equilibrated ensemble of clusters with different structures, spin multiplicities, and ground-state energies. We calculate the physical properties of this system by weighting the individual configurations according to the Boltzmann statistics. We find that presence of isomers with very similar ground-state energies, yet very different magnetic properties, gives rise to a rich magnetic behavior of the system which differs significantly from what would be expected for single configurations. We apply the present model to determine the magnetic susceptibility of a cluster ensemble of Langevin paramagnets. Our results show that some of the anomalies in the magnetic behavior of transition-metal clusters might be understood in the framework of our model which is, of course, limited by the extremely high computational effort needed to obtain the input data.

scholarly journals Term rules for simple metal clusters

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Daisuke Yoshida ◽  
Hannes Raebiger
Keyword(s):  
Ground State ◽  
Metal Clusters ◽  
Ground States ◽  
Simple Metal ◽  
Relative Stabilities ◽  
Atom Clusters ◽  
Benchmark Calculation ◽  
Simple Rules ◽  
Guiding Principles

Abstract Hund’s term rules are only valid for isolated atoms, but have no generalization for molecules or clusters of several atoms. We present a benchmark calculation of Al2 and Al3, for which we find the high and low-spin ground states 3Π u and "Equation missing", respectively. We show that the relative stabilities of all the molecular terms of Al2 and Al3 can be described by simple rules pertaining to bonding structures and symmetries, which serve as guiding principles to determine ground state terms of arbitrary multi-atom clusters.

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