Onset of simple liquid behaviour in modified water models

Area of Science:

• Computational chemistry
• Statistical mechanics
• Soft matter physics

Background:

• Understanding simple liquid behavior is crucial for various scientific fields.
• Hybrid water models allow tuning potential energy contributions to mimic different fluid characteristics.
• Inverse power law fluids serve as a reference for simple liquid behavior.

Purpose of the Study:

• To investigate the transition to simple liquid behavior in modified hybrid water models.
• To examine how enhancing Lennard-Jones interactions affects fluid properties.
• To assess the applicability of theoretical frameworks like energy-virial correlations and scaling laws.

Main Methods:

• Simulations of modified hybrid water models with varying Lennard-Jones to electrostatic contributions.
• Analysis of configurational energy-virial correlations.
• Examination of excess entropy's temperature dependence along isochores.
• Investigation of thermodynamic and excess entropy scaling of diffusivities.

Main Results:

• Increasing Lennard-Jones contribution strengthens configurational energy-virial correlations.
• The Rosenfeld-Tarazona temperature dependence of excess entropy holds across all studied hybrid models.
• Thermodynamic scaling is observed in weakly polar fluids with moderate energy-virial correlations.
• Rosenfeld-scaling of transport properties is not strictly tied to energy-virial correlations strength.

Conclusions:

• Modified water models provide a platform to study the transition to simple liquid behavior.
• Energy-virial correlations and scaling laws offer insights into fluid thermodynamics and dynamics.
• The findings contribute to a deeper understanding of liquid-state physics and the universality of fluid behavior.