Diffusion of single adatoms of platinum, iridium and gold on platinum surfaces

Bassett, Duncan; Webber, Philip

doi:10.1016/0039-6028(78)90429-6

Cited by 323 publications

(76 citation statements)

References 18 publications

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“…Interatomic interactions are in the form of Morse potential with parameters chosen to reproduce the diffusion barrier on Pt surfaces. 38 This case offers an opportunity to illustrate another feature of the algorithm, the flexibility to activate any subspace of the full 3N +1−D space. For example, if we decide to activate a single corner atom in the adcluster, 3N = 3, we would find an activation energy of 1.695 eV, as shown in Fig.…”

Section: Appendix A: Benchmarking Basin Filling Algorithmmentioning

confidence: 99%

Computing the viscosity of supercooled liquids

Kushima

Lin

et al. 2009

The Journal of Chemical Physics

139

184

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We describe an atomistic method for computing the viscosity of highly viscous liquids based on activated state kinetics. A basin-filling algorithm allowing the system to climb out of deep energy minima through a series of activation and relaxation is proposed and first benchmarked on the problem of adatom diffusion on a metal surface. It is then used to generate transition state pathway trajectories in the potential energy landscape of a binary Lennard-Jones system. Analysis of a sampled trajectory shows the system moves from one deep minimum to another by a process that involves high activation energy and the crossing of many local minima and saddle points. To use the trajectory data to compute the viscosity we derive a Markov Network model within the Green-Kubo formalism and show that it is capable of producing the temperature dependence in the low-viscosity regime described by molecular dynamics simulation, and in the high-viscosity regime (10(2)-10(12) Pa s) shown by experiments on fragile glass-forming liquids. We also derive a mean-field-like description involving a coarse-grained temperature-dependent activation barrier, and show it can account qualitatively for the fragile behavior. From the standpoint of molecular studies of transport phenomena this work provides access to long relaxation time processes beyond the reach of current molecular dynamics capabilities. In a companion paper we report a similar study of silica, a representative strong liquid. A comparison of the two systems gives insight into the fundamental difference between strong and fragile temperature variations. We describe an atomistic method for computing the viscosity of highly viscous liquids based on activated state kinetics. A basin-filling algorithm allowing the system to climb out of deep energy minima through a series of activation and relaxation is proposed and first benchmarked on the problem of adatom diffusion on a metal surface. It is then used to generate transition state pathway trajectories in the potential energy landscape of a binary Lennard-Jones system. Analysis of a sampled trajectory shows the system moves from one deep minimum to another by a process that involves high activation energy and the crossing of many local minima and saddle points. To use the trajectory data to compute the viscosity we derive a Markov Network model within the Green-Kubo formalism and show that it is capable of producing the temperature dependence in the low-viscosity regime described by molecular dynamics simulation, and in the high-viscosity regime ͑10 2 -10 12 Pa s͒ shown by experiments on fragile glass-forming liquids. We also derive a mean-field-like description involving a coarse-grained temperature-dependent activation barrier, and show it can account qualitatively for the fragile behavior. From the standpoint of molecular studies of transport phenomena this work provides access to long relaxation time processes beyond the reach of current molecular dynamics capabilities. In a companion paper we report a similar study of ...

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Section: Appendix A: Benchmarking Basin Filling Algorithmmentioning

confidence: 99%

Computing the viscosity of supercooled liquids

Kushima

Lin

et al. 2009

The Journal of Chemical Physics

139

184

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“…In this case, the energies were calculated with the Morse potential. 49,50 The geometry optimization was done with high accuracy and therefore a big gap is visible in all cases. Fig.…”

Section: Numerical Testsmentioning

confidence: 99%

A fingerprint based metric for measuring similarities of crystalline structures

Zhu

Amsler

Fuhrer

et al. 2016

The Journal of Chemical Physics

130

124

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Measuring similarities/dissimilarities between atomic structures is important for the exploration of potential energy landscapes. However, the cell vectors together with the coordinates of the atoms, which are generally used to describe periodic systems, are quantities not directly suitable as fingerprints to distinguish structures. Based on a characterization of the local environment of all atoms in a cell, we introduce crystal fingerprints that can be calculated easily and define configurational distances between crystalline structures that satisfy the mathematical properties of a metric. This distance between two configurations is a measure of their similarity/dissimilarity and it allows in particular to distinguish structures. The new method can be a useful tool within various energy landscape exploration schemes, such as minima hopping, random search, swarm intelligence algorithms, and high-throughput screenings. C 2016 AIP Publishing LLC. [http://dx

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“…If the assumptions made by Tung and Graham (1980) are reasonable, all models are in good agreement with experiment for diffusion on the (100) surface, but agreement is poor for the Ni(1l) surface. Recent lattice statics calculations (Liu, Cohen, Adams, and Voter 1991) using the VC and another set (Adams, Foiles, and Wolfer 1989) exchange (Bassett and Webber 1978;Halicioglu and Pound 1979) is included in Section 3.3.3.…”

Section: Comparison With Exneriment Experimental Results Presented Amentioning

confidence: 99%