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Title: Long-time atomistic dynamics through a new self-adaptive accelerated molecular dynamics method

Abstract

A self-adaptive accelerated molecular dynamics method is developed to model infrequent atomic- scale events, especially those events that occur on a rugged free-energy surface. Key in the new development is the use of the total displacement of the system at a given temperature to construct a boost-potential, which is slowly increased to accelerate the dynamics. The temperature is slowly increased to accelerate the dynamics. By allowing the system to evolve from one steady-state con guration to another by overcoming the transition state, this self-evolving approach makes it possible to explore the coupled motion of species that migrate on vastly different time scales. The migrations of single vacancy (V) and small He-V clusters, and the growth of nano-sized He-V clusters in Fe for times in the order of seconds are studied by this new method. An interstitial- assisted mechanism is rst explored for the migration of a helium-rich He-V cluster, while a new two-component Ostwald ripening mechanism is suggested for He-V cluster growth.

Authors:
; ; ; ; ;
Publication Date:
Research Org.:
Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1353318
Report Number(s):
PNNL-SA-112547
Journal ID: ISSN 0953-8984; AT2030110
DOE Contract Number:  
AC05-76RL01830
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Physics. Condensed Matter; Journal Volume: 29; Journal Issue: 14
Country of Publication:
United States
Language:
English

Citation Formats

Gao, N., Yang, L., Gao, F., Kurtz, R. J., West, D., and Zhang, S.. Long-time atomistic dynamics through a new self-adaptive accelerated molecular dynamics method. United States: N. p., 2017. Web. doi:10.1088/1361-648X/aa574b.
Gao, N., Yang, L., Gao, F., Kurtz, R. J., West, D., & Zhang, S.. Long-time atomistic dynamics through a new self-adaptive accelerated molecular dynamics method. United States. doi:10.1088/1361-648X/aa574b.
Gao, N., Yang, L., Gao, F., Kurtz, R. J., West, D., and Zhang, S.. Mon . "Long-time atomistic dynamics through a new self-adaptive accelerated molecular dynamics method". United States. doi:10.1088/1361-648X/aa574b.
@article{osti_1353318,
title = {Long-time atomistic dynamics through a new self-adaptive accelerated molecular dynamics method},
author = {Gao, N. and Yang, L. and Gao, F. and Kurtz, R. J. and West, D. and Zhang, S.},
abstractNote = {A self-adaptive accelerated molecular dynamics method is developed to model infrequent atomic- scale events, especially those events that occur on a rugged free-energy surface. Key in the new development is the use of the total displacement of the system at a given temperature to construct a boost-potential, which is slowly increased to accelerate the dynamics. The temperature is slowly increased to accelerate the dynamics. By allowing the system to evolve from one steady-state con guration to another by overcoming the transition state, this self-evolving approach makes it possible to explore the coupled motion of species that migrate on vastly different time scales. The migrations of single vacancy (V) and small He-V clusters, and the growth of nano-sized He-V clusters in Fe for times in the order of seconds are studied by this new method. An interstitial- assisted mechanism is rst explored for the migration of a helium-rich He-V cluster, while a new two-component Ostwald ripening mechanism is suggested for He-V cluster growth.},
doi = {10.1088/1361-648X/aa574b},
journal = {Journal of Physics. Condensed Matter},
number = 14,
volume = 29,
place = {United States},
year = {Mon Feb 27 00:00:00 EST 2017},
month = {Mon Feb 27 00:00:00 EST 2017}
}