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Strong pressure-energy correlations in van der Waals liquids

Ulf R. Pedersen·Nicholas Bailey·Thomas B. Schrøder·Jeppe C. Dyre
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Abstract

Strong correlations between equilibrium fluctuations of the configurational parts of pressure and energy are found in the Lennard-Jones liquid and other simple liquids, but not in hydrogen-bonding liquids like methanol and water. The correlations, that are present also in the crystal and glass phases, reflect an effective inverse power-law repulsive potential dominating fluctuations, even at zero and slightly negative pressure. In experimental data for supercritical Argon, the correlations are found to be approximately 96%. Consequences for viscous liquid dynamics are discussed.

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Ulf R. Pedersen, Nicholas Bailey, Thomas B. Schrøder, Jeppe C. Dyre. 2007-11-22. Strong pressure-energy correlations in van der Waals liquids. https://doi.org/10.1103/physrevlett.100.015701

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