Statistics of small length scale density fluctuations in supercooled viscous liquids

Research output: Contribution to journalJournal articleResearchpeer-review

Abstract

Many successful theories of liquids near the melting temperature assume that small length scale density fluctuations follow Gaussian statistics. This paper presents a numerical investigation of density fluctuations in the supercooled viscous regime using an enhanced sampling method. Five model systems are investigated: the single component Lennard-Jones liquid, the Kob-Andersen binary mixture, the Wahnström binary mixture, the Lewis-Wahnström model of ortho-terphenyl, and the TIP4P/Ice model of water. The results show that the Gaussian approximation persists to a good degree into the supercooled viscous regime; however, it is less accurate at low temperatures. The analysis suggests that non-Gaussian fluctuations are related to crystalline configurations. Implications for theories of the glass transition are discussed.
Original languageEnglish
Article number094505
JournalJournal of Chemical Physics
Volume2019
Issue number150
Number of pages11
ISSN0021-9606
DOIs
Publication statusPublished - 4 Mar 2019

Cite this

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title = "Statistics of small length scale density fluctuations in supercooled viscous liquids",
abstract = "Many successful theories of liquids near the melting temperature assume that small length scale density fluctuations follow Gaussian statistics. This paper presents a numerical investigation of density fluctuations in the supercooled viscous regime using an enhanced sampling method. Five model systems are investigated: the single component Lennard-Jones liquid, the Kob-Andersen binary mixture, the Wahnstr{\"o}m binary mixture, the Lewis-Wahnstr{\"o}m model of ortho-terphenyl, and the TIP4P/Ice model of water. The results show that the Gaussian approximation persists to a good degree into the supercooled viscous regime; however, it is less accurate at low temperatures. The analysis suggests that non-Gaussian fluctuations are related to crystalline configurations. Implications for theories of the glass transition are discussed.",
author = "Pedersen, {Ulf R{\o}rb{\ae}k}",
year = "2019",
month = "3",
day = "4",
doi = "10.1063/1.5080277",
language = "English",
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journal = "Journal of Chemical Physics",
issn = "0021-9606",
publisher = "American Institute of Physics",
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Statistics of small length scale density fluctuations in supercooled viscous liquids. / Pedersen, Ulf Rørbæk.

In: Journal of Chemical Physics, Vol. 2019, No. 150, 094505, 04.03.2019.

Research output: Contribution to journalJournal articleResearchpeer-review

TY - JOUR

T1 - Statistics of small length scale density fluctuations in supercooled viscous liquids

AU - Pedersen, Ulf Rørbæk

PY - 2019/3/4

Y1 - 2019/3/4

N2 - Many successful theories of liquids near the melting temperature assume that small length scale density fluctuations follow Gaussian statistics. This paper presents a numerical investigation of density fluctuations in the supercooled viscous regime using an enhanced sampling method. Five model systems are investigated: the single component Lennard-Jones liquid, the Kob-Andersen binary mixture, the Wahnström binary mixture, the Lewis-Wahnström model of ortho-terphenyl, and the TIP4P/Ice model of water. The results show that the Gaussian approximation persists to a good degree into the supercooled viscous regime; however, it is less accurate at low temperatures. The analysis suggests that non-Gaussian fluctuations are related to crystalline configurations. Implications for theories of the glass transition are discussed.

AB - Many successful theories of liquids near the melting temperature assume that small length scale density fluctuations follow Gaussian statistics. This paper presents a numerical investigation of density fluctuations in the supercooled viscous regime using an enhanced sampling method. Five model systems are investigated: the single component Lennard-Jones liquid, the Kob-Andersen binary mixture, the Wahnström binary mixture, the Lewis-Wahnström model of ortho-terphenyl, and the TIP4P/Ice model of water. The results show that the Gaussian approximation persists to a good degree into the supercooled viscous regime; however, it is less accurate at low temperatures. The analysis suggests that non-Gaussian fluctuations are related to crystalline configurations. Implications for theories of the glass transition are discussed.

UR - http://glass.ruc.dk/pdf/articles/2019_JChemPhys_150_094505.pdf

U2 - 10.1063/1.5080277

DO - 10.1063/1.5080277

M3 - Journal article

VL - 2019

JO - Journal of Chemical Physics

JF - Journal of Chemical Physics

SN - 0021-9606

IS - 150

M1 - 094505

ER -