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Title: Accelerating the dynamics of infrequent events: Combining hyperdynamics and parallel replica dynamics to treat epitaxial layer growth

Abstract

During the growth of a surface, morphology-controlling diffusion events occur over time scales that far exceed those accessible to molecular dynamics (MD) simulation. Kinetic Monte Carlo offers a way to reach much longer times, but suffers from the fact that the dynamics are correct only if all possible diffusion events are specified in advance. This is difficult due to the concerted nature of many of the recently discovered surface diffusion mechanisms and the complex configurations that arise during real growth. Here the authors describe two new approaches for this type of problem. The first, hyperdynamics, is an accelerated MD method, in which the trajectory is run on a modified potential energy surface and time is accumulated as a statistical property. Relative to regular MD, hyperdynamics can give computational gains of more than 10{sup 2}. The second method offers a way to parallelize the dynamics efficiently for systems too small for conventional parallel MD algorithms. Both methods exploit the infrequent-event nature of the diffusion process. After an introductory description of these methods, the authors present preliminary results from simulations combining the two approaches to reach near-millisecond time scales on systems relevant to epitaxial metal growth.

Authors:
;
Publication Date:
Research Org.:
Los Alamos National Lab., Theoretical Div., NM (United States)
Sponsoring Org.:
USDOE Office of Energy Research, Washington, DC (United States)
OSTI Identifier:
304117
Report Number(s):
LA-UR-98-2136; CONF-980405-
ON: DE99000751; TRN: AHC29904%%193
DOE Contract Number:  
W-7405-ENG-36
Resource Type:
Conference
Resource Relation:
Conference: Spring meeting of the Materials Research Society, San Francisco, CA (United States), 13-17 Apr 1998; Other Information: PBD: [1998]
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; METALS; EPITAXY; CALCULATION METHODS; DIFFUSION; CRYSTAL GROWTH; MOLECULAR DYNAMICS METHOD; TIME DEPENDENCE

Citation Formats

Voter, A F, and Germann, T C. Accelerating the dynamics of infrequent events: Combining hyperdynamics and parallel replica dynamics to treat epitaxial layer growth. United States: N. p., 1998. Web.
Voter, A F, & Germann, T C. Accelerating the dynamics of infrequent events: Combining hyperdynamics and parallel replica dynamics to treat epitaxial layer growth. United States.
Voter, A F, and Germann, T C. 1998. "Accelerating the dynamics of infrequent events: Combining hyperdynamics and parallel replica dynamics to treat epitaxial layer growth". United States. https://www.osti.gov/servlets/purl/304117.
@article{osti_304117,
title = {Accelerating the dynamics of infrequent events: Combining hyperdynamics and parallel replica dynamics to treat epitaxial layer growth},
author = {Voter, A F and Germann, T C},
abstractNote = {During the growth of a surface, morphology-controlling diffusion events occur over time scales that far exceed those accessible to molecular dynamics (MD) simulation. Kinetic Monte Carlo offers a way to reach much longer times, but suffers from the fact that the dynamics are correct only if all possible diffusion events are specified in advance. This is difficult due to the concerted nature of many of the recently discovered surface diffusion mechanisms and the complex configurations that arise during real growth. Here the authors describe two new approaches for this type of problem. The first, hyperdynamics, is an accelerated MD method, in which the trajectory is run on a modified potential energy surface and time is accumulated as a statistical property. Relative to regular MD, hyperdynamics can give computational gains of more than 10{sup 2}. The second method offers a way to parallelize the dynamics efficiently for systems too small for conventional parallel MD algorithms. Both methods exploit the infrequent-event nature of the diffusion process. After an introductory description of these methods, the authors present preliminary results from simulations combining the two approaches to reach near-millisecond time scales on systems relevant to epitaxial metal growth.},
doi = {},
url = {https://www.osti.gov/biblio/304117}, journal = {},
number = ,
volume = ,
place = {United States},
year = {Thu Dec 31 00:00:00 EST 1998},
month = {Thu Dec 31 00:00:00 EST 1998}
}

Conference:
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