Onset of simple liquid behaviour in modified water models

Journal Article · Mon Apr 28 04:00:00 EDT 2014 · Journal of Chemical Physics

DOI:https://doi.org/10.1063/1.4870823· OSTI ID:22253085

Prasad, Saurav; Chakravarty, Charusita ^[1]

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1. Department of Chemistry, Indian Institute of Technology-Delhi, New Delhi 110016 (India)

The transition to simple liquid behaviour is studied in a set of modified hybrid water models where the potential energy contribution of the Lennard-Jones dispersion-repulsion contribution is progressively enhanced relative to the electrostatic contribution. Characteristics of simple liquid behaviour that indicate the extent to which a given system can be mapped onto an inverse power law fluid are examined, including configurational energy-virial correlations, functional form of temperature dependence of the excess entropy along isochores, and thermodynamic and excess entropy scaling of diffusivities. As the Lennard-Jones contribution to the potential energy function increases, the strength of the configurational energy-virial correlations increases. The Rosenfeld-Tarazona temperature dependence of the excess entropy is found to hold for the range of state points studied here for all the hybrid models, regardless of the degree of correlating character. Thermodynamic scaling is found to hold for weakly polar fluids with a moderate degree of energy-virial correlations. Rosenfeld-scaling of transport properties is found not to be necessarily linked with the strength of energy-virial correlations but may hold for systems with poor thermodynamic scaling if diffusivities and excess entropies show correlated departures from the isomorph-invariant behaviour characteristic of approximate inverse power law fluids. The state-point dependence of the configurational energy-virial correlation coefficient and the implications for thermodynamic and excess entropy scalings are considered.

• OSTI ID: 22253085
• Journal Information: Journal of Chemical Physics, Journal Name: Journal of Chemical Physics Journal Issue: 16 Vol. 140; ISSN JCPSA6; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
DISPERSIONS
ENTROPY
HYBRIDIZATION
LIQUIDS
POTENTIAL ENERGY
TEMPERATURE DEPENDENCE
WATER