From Topographies to Dynamics on Multidimensional Potential Energy Surfaces of Atomic Clusters

Three related clusters of thirteen particles bound by pairwise Morse potentials with different ranges are the vehicles for relating the dynamics and kinetics of these clusters to the topographies of their energy landscapes. The analyses are based on the distributions of minima and saddles, on the asymmetries of the barriers and the kinetics of passage among the energy bands that the distributions of minima display. While all three of the examples are essentially structure-seekers, the extent of this character is clearly related to the range of the potential.

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“…with F ) 4, there are many transitions from all bands to the GM band (6). The peak in the frequency of transitions to the GM occurs at band 3.…”

Section: Band Transitionsmentioning

confidence: 99%

“…This is in contrast to some larger Lennard-Jones and Morse clusters, which are good examples of glass-formers. 6 The F parameter of the Morse potential varies the potential's range: the smaller the value of F, the longer the range of the potential. Morse potentials fit to known diatomic molecule spectra have values of F between 3 and 7.…”

Section: Introductionmentioning

confidence: 99%

Characterizing Potential Surface Topographies through the Distribution of Saddles and Minima

2006

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“…This characterization of the PES helps to explain the initial presence of the metastable isomers in the experiments by Jarrold and coworkers. [14,15] The energy landscape efficiently 'funnels' high energy structures into rocksalt-type minima [52,53]. However, the barriers between the different funnels are large, leading to a separation of time scales for relaxation down the PES to a rocksalt structure and conversion of the metastable nanocrystals to the global minimum.…”

Section: Global Optimizationmentioning

confidence: 99%

Structural transitions and global minima of sodium chloride clusters

Doye

Wales²

1999

Phys. Rev. B

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101

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In recent experiments on sodium chloride clusters structural transitions between nanocrystals with different cuboidal shapes were detected. Here we determine reaction pathways between the low energy isomers of one of these clusters, (NaCl)35Cl − . The key process in these structural transitions is a highly cooperative rearrangement in which two parts of the nanocrystal slip past one another on a {110} plane in a 110 direction. In this way the nanocrystals can plastically deform, in contrast to the brittle behaviour of bulk sodium chloride crystals at the same temperatures; the nanocrystals have mechanical properties which are a unique feature of their finite size. We also report and compare the global potential energy minima for (NaCl) N Cl − using two empirical potentials, and comment on the effect of polarization. 61.46.+w,36.40.Sx,82.30.Qt

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“…For years, potential energy surfaces have been widely studied and regarded as an important tool to understand kinetics and dynamics of various systems from the relaxation of atomic clusters [1][2][3] to the problems of protein folding. 4 Recently, master equation dynamics, 5 as a method complementary to molecular dynamics (MD), has also been applied to the study of kinetics on a PES.…”

Section: Introductionmentioning

confidence: 99%

“…Ball and Berry 11 first addressed this problem by using a ''sequence sampling'' method to obtain samples of some preknown full PESs of Ar 11 and Ar 13 . The authors have shown that with ''sequence sampling'', the constructed sample PES can be used to predict the slowest relaxation mode with convergence to within better than a factor of two with about 100 monotonic sequences 2,3 where each sequence is a ''minimum-saddle-minimum-...-minimum'' series with monotonically increasing energy values for the minima. This corresponds to about 40% and 20% of the sampling ratio (defined as the ratio between the numbers of energy minima in the sample PES and in the full PES) for the full PESs of Ar 11 and Ar 13 , respectively.…”

Section: Introductionmentioning

confidence: 99%

Kinetics of model energy landscapes: an approach to complex systems

Lü

Zhang

Berry

2005

Phys. Chem. Chem. Phys.

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An idealized potential energy surface (PES), simply a PES-like network of stationary points, is demonstrated to be a useful tool to study kinetic relaxation of complex energy landscapes. Combined with a master equation, we show that if constructed with proper regularity, the kinetics of the PES is easy to predict and understand by carefully examining the eigenmodes of the master equation. By modifying the idealized PES model to make it more and more complicated, we demonstrate a systematic method to study the complex kinetics on large PES. The idealized PES model is used to explore the feasibility and the robustness of statistical sampling of large PES. We develop several sampling strategies, such as the ''rough topography sampling'' and the ''low barrier saddle sampling'' in the idealized PES model and find they are also applicable to a realistic PES of the 13-atom Morse cluster with range parameter r ¼ 6. To measure the robustness of the sampling methods, we compare the eigenvalue spectra, the eigenvector similarity and the relaxation times of the total energy of the full and sample PESs.

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From Topographies to Dynamics on Multidimensional Potential Energy Surfaces of Atomic Clusters

Cited by 190 publications

References 36 publications

Characterizing Potential Surface Topographies through the Distribution of Saddles and Minima

Characterizing Potential Surface Topographies through the Distribution of Saddles and Minima

Structural transitions and global minima of sodium chloride clusters

Kinetics of model energy landscapes: an approach to complex systems

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