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arXiv · 1807.10958

The EXP pair-potential system. II. Fluid phase isomorphs

Andreas Kvist Bacher·Thomas B. Schrøder·Jeppe C. Dyre
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Abstract

This paper continues the investigation of the exponentially repulsive EXP pair-potential system of Paper I with a focus on isomorphs in the low-temperature gas and liquid phases. As expected from the EXP system's strong virial potential-energy correlations, the system's reduced-unit structure and dynamics are isomorph invariant to a good approximation. Three methods for generating isomorphs are compared: the small-step method that is exact in the limit of small density changes and two versions of the direct-isomorph-check method that allows for much larger density changes. Results from approximate methods are compared to those of the small-step method for each of three isomorphs generated by 230 one percent density increases, covering in all one decade of density variation. Both approximate methods work well.

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Andreas Kvist Bacher, Thomas B. Schrøder, Jeppe C. Dyre. 2018-09-10. The EXP pair-potential system. II. Fluid phase isomorphs. https://doi.org/10.1063/1.5043548

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