User-friendly, theory-based web applet for rapidly predicting structure and thermodynamics of complex fluids

TL;DR

This paper introduces a user-friendly web applet based on a recent analytical strategy that enables rapid, semi-quantitative predictions of the structure and thermodynamics of complex fluids from pair interactions, useful for education and research.

Contribution

It presents a novel web applet that applies an analytical method to estimate fluid properties from pair interactions, enhancing accessibility and understanding in statistical mechanics.

Findings

The applet effectively predicts radial distribution functions and thermodynamic properties.

It demonstrates the transition from ideal gas to correlated liquid behavior.

It captures key features of water-like liquids with ramp-shaped repulsions.

Abstract

Based on a recently introduced analytical strategy [Hollingshead et al., J. Chem. Phys. 139, 161102 (2013)], we present a web applet that can quickly and semi-quantitatively estimate the equilibrium radial distribution function and related thermodynamic properties of a fluid from knowledge of its pair interaction. We present a detailed description of the applet's features and intended workflow, followed by a description of how the applet can be used to illustrate two (of many possible) concepts of interest for introductory statistical mechanics courses: the transition from ideal gas-like behavior to correlated-liquid behavior with increasing density and the tradeoff between dominant length scales with changing temperature in a system with ramp-shaped repulsions. The latter type of interaction qualitatively captures distinctive thermodynamic properties of liquid water because its energetic bias toward locally open structures mimics that of water's hydrogen-bond network.