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arXiv · 1508.01117

Molecular-scale remnants of the liquid-gas transition in supercritical polar fluids

V. P. Sokhan·A. Jones·F. S. Cipcigan·J. Crain·G. J. Martyna
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Abstract

An electronically coarse-grained model for water reveals a persistent vestige of the liquid-gas transition deep into the supercritical region. A crossover in the density dependence of the molecular dipole arises from the onset of non-percolating hydrogen bonds. The crossover points coincide with the Widom line in the scaling region but extend further, tracking the heat capacity maxima, offering evidence for liquid- and gas-like state points in a "one-phase" fluid. The effect is present even in dipole-limit models suggesting that it is common for all molecular liquids exhibiting dipole enhancement in the liquid phase.

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V. P. Sokhan, A. Jones, F. S. Cipcigan, J. Crain, G. J. Martyna. 2015-08-05. Molecular-scale remnants of the liquid-gas transition in supercritical polar fluids. https://doi.org/10.1103/physrevlett.115.117801

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