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Unexpected finite size effects in interfacial systems: why bigger is not always better - increase in uncertainty of surface tension with bulk phase width

Longford, Francis G.J., Essex, Jonathan W., Skylaris, Chris-Kriton and Frey, Jeremy G. (2018) Unexpected finite size effects in interfacial systems: why bigger is not always better - increase in uncertainty of surface tension with bulk phase width. The Journal of Chemical Physics, 148 (21), 1-12.

Record type: Article

Abstract

We present an unexpected finite size effect affecting interfacial molecular simulations that is proportional to the width-to-surface-area ratio of the bulk phase $L_l / A$. This finite size effect has a significant impact on the variance of surface tension values calculated using the virial summation method. A theoretical derivation of the origin of the effect is proposed, giving a new insight into the importance of optimising system dimensions in interfacial simulations. We demonstrate the consequences of this finite size effect via a new way to estimate the surface energetic and entropic properties of simulated air-liquid interfaces. Our method is based on macroscopic thermodynamic theory and involves comparing the internal energies of systems with varying dimensions. We present the testing of these methods using simulations of the TIP4P/2005 water forcefield and a Lennard-Jones fluid model of argon. Finally, we provide suggestions of additional situations in which this finite size effect is expected to be significant, as well as possible ways to avoid its impact.

Text pdf_archiveJCPSA6vol_148iss_21214704_1_am - Accepted Manuscript

Accepted/In Press date: 18 May 2018
e-pub ahead of print date: 5 June 2018

Identifiers

Local EPrints ID: 421639
URI: https://eprints.soton.ac.uk/id/eprint/421639
ISSN: 0021-9606
PURE UUID: 3e624fa4-635f-46e3-8e0d-cd841735cf05
ORCID for Jonathan W. Essex: orcid.org/0000-0003-2639-2746
ORCID for Chris-Kriton Skylaris: orcid.org/0000-0003-0258-3433
ORCID for Jeremy G. Frey: orcid.org/0000-0003-0842-4302

Catalogue record

Date deposited: 18 Jun 2018 16:30

Contributors

Author: Francis G.J. Longford
Author: Jeremy G. Frey