Fluctuation profiles in inhomogeneous fluids

TL;DR

This paper introduces fluctuation profiles based on local energy, entropy, and particle number fluctuations to describe inhomogeneous fluids, supported by theoretical derivations and computer simulations.

Contribution

It develops a new framework for analyzing local fluctuations in inhomogeneous fluids using functional generators and Ornstein-Zernike relations.

Findings

Fluctuation profiles differ significantly among Lennard-Jones, hard sphere, and Gaussian core fluids.

Profiles derived from thermodynamic derivatives match simulation results.

The approach provides insight into local fluctuation behavior in confined fluids.

Abstract

Three one-body profiles that correspond to local fluctuations in energy, in entropy, and in particle number are used to describe the equilibrium properties of inhomogeneous classical many-body systems. Local fluctuations are obtained from thermodynamic differentiation of the density profile or equivalently from average microscopic covariances. The fluctuation profiles follow from functional generators and they satisfy Ornstein-Zernike relations. Computer simulations reveal markedly different fluctuations in confined fluids with Lennard-Jones, hard sphere, and Gaussian core interactions.