Connecting entropy scaling and density scaling

Ian H Bell; Robin Fingerhut; Jadran Vrabec; Lorenzo Costigliola

doi:10.1063/5.0097088

Connecting entropy scaling and density scaling

J Chem Phys. 2022 Aug 21;157(7):074501. doi: 10.1063/5.0097088.

Authors

Ian H Bell¹, Robin Fingerhut², Jadran Vrabec², Lorenzo Costigliola³

Affiliations

¹ Applied Chemicals and Materials Division, National Institute of Standards and Technology, Boulder, Colorado 80305, USA.
² Thermodynamics and Process Engineering, Technische Universität Berlin, Ernst-Reuter-Platz 1, 10587 Berlin, Germany.
³ Department of Science and Environment, Roskilde University, P.O. BOX 260, DK-4000 Roskilde, Denmark.

PMID: 35987579
DOI: 10.1063/5.0097088

Abstract

It is shown that the residual entropy (entropy minus that of the ideal gas at the same temperature and density) is mostly synonymous with the independent variable of density scaling, identifying a direct link between these two approaches. The residual entropy and the effective hardness of interaction (itself a derivative at constant residual entropy) are studied for the Lennard-Jones monomer and dimer as well as a range of rigid molecular models for carbon dioxide. It is observed that the density scaling exponent appears to be related to the two-body interactions in the dilute-gas limit.