Atomic motion from the mean square displacement in a monatomic liquid

Wallace, Duane C.; De Lorenzi-Venneri, Giulia; Chisolm, Eric D.

doi:10.1088/0953-8984/28/18/185101

Title: Atomic motion from the mean square displacement in a monatomic liquid

Abstract

V-T theory is constructed in the many-body Hamiltonian formulation, and is being developed as a novel approach to liquid dynamics theory. In this theory the liquid atomic motion consists of two contributions, normal mode vibrations in a single representative potential energy valley, and transits, which carry the system across boundaries between valleys. The mean square displacement time correlation function (the MSD) is a direct measure of the atomic motion, and our goal is to determine if the V-T formalism can produce a physically sensible account of this motion. We employ molecular dynamics (MD) data for a system representing liquid Na, and find the motion evolves in three successive time intervals: on the first 'vibrational' interval, the vibrational motion alone gives a highly accurate account of the MD data; on the second 'crossover' interval, the vibrational MSD saturates to a constant while the transit motion builds up from zero; on the third 'random walk' interval, the transit motion produces a purely diffusive random walk of the vibrational equilibrium positions. Furthermore, this motional evolution agrees with, and adds refinement to, the MSD atomic motion as described by current liquid dynamics theories.

Authors:

Wallace, Duane C. ^[1]; De Lorenzi-Venneri, Giulia ^[1]; Chisolm, Eric D. ^[2]

Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Descartes Labs, Los Alamos, NM (United States)

Publication Date:: Fri Apr 08 00:00:00 EDT 2016

Research Org.:: Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)

Sponsoring Org.:: USDOE

OSTI Identifier:: 1291293

Report Number(s):: LA-UR-15-26631
Journal ID: ISSN 0953-8984

Grant/Contract Number:: AC52-06NA25396

Resource Type:: Accepted Manuscript

Journal Name:: Journal of Physics. Condensed Matter

Additional Journal Information:: Journal Volume: 28; Journal Issue: 18; Journal ID: ISSN 0953-8984

Publisher:: IOP Publishing

Country of Publication:: United States

Language:: English

Subject:: 74 ATOMIC AND MOLECULAR PHYSICS; Theory, Liquids, Selfdiffusion; Liquid theory; Hamiltonian; atomic motion in liquids; statistical mechanics

Citation Formats


                    Wallace, Duane C., De Lorenzi-Venneri, Giulia, and Chisolm, Eric D. Atomic motion from the mean square displacement in a monatomic liquid.  United States: N. p., 2016. 
Web.  doi:10.1088/0953-8984/28/18/185101.

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                    Wallace, Duane C., De Lorenzi-Venneri, Giulia, & Chisolm, Eric D. Atomic motion from the mean square displacement in a monatomic liquid.  United States.  https://doi.org/10.1088/0953-8984/28/18/185101

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                    Wallace, Duane C., De Lorenzi-Venneri, Giulia, and Chisolm, Eric D. Fri .  
"Atomic motion from the mean square displacement in a monatomic liquid".  United States.  https://doi.org/10.1088/0953-8984/28/18/185101.  https://www.osti.gov/servlets/purl/1291293.

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@article{osti_1291293,

  title        = {Atomic motion from the mean square displacement in a monatomic liquid},

  author       = {Wallace, Duane C. and De Lorenzi-Venneri, Giulia and Chisolm, Eric D.},

  abstractNote = {V-T theory is constructed in the many-body Hamiltonian formulation, and is being developed as a novel approach to liquid dynamics theory. In this theory the liquid atomic motion consists of two contributions, normal mode vibrations in a single representative potential energy valley, and transits, which carry the system across boundaries between valleys. The mean square displacement time correlation function (the MSD) is a direct measure of the atomic motion, and our goal is to determine if the V-T formalism can produce a physically sensible account of this motion. We employ molecular dynamics (MD) data for a system representing liquid Na, and find the motion evolves in three successive time intervals: on the first 'vibrational' interval, the vibrational motion alone gives a highly accurate account of the MD data; on the second 'crossover' interval, the vibrational MSD saturates to a constant while the transit motion builds up from zero; on the third 'random walk' interval, the transit motion produces a purely diffusive random walk of the vibrational equilibrium positions. Furthermore, this motional evolution agrees with, and adds refinement to, the MSD atomic motion as described by current liquid dynamics theories.},

  doi          = {10.1088/0953-8984/28/18/185101},

  journal      = {Journal of Physics. Condensed Matter},

  number       = 18,

  volume       = 28,

  place        = {United States},

  year         = {Fri Apr 08 00:00:00 EDT 2016},

  month        = {Fri Apr 08 00:00:00 EDT 2016}

}

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Works referencing / citing this record:

Identifying short- and long-time modes of the mean-square displacement: An improved nonlinear fitting approach
journal, May 2019

Riahi, M. K.; Qattan, I. A.; Hassan, J.
AIP Advances, Vol. 9, Issue 5
DOI: 10.1063/1.5098051

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Title: Atomic motion from the mean square displacement in a monatomic liquid

Abstract

Citation Formats

Identifying short- and long-time modes of the mean-square displacement: An improved nonlinear fitting approach journal, May 2019

Identifying short- and long-time modes of the mean-square displacement: An improved nonlinear fitting approach
journal, May 2019