Mean-field dynamical density functional theory

TL;DR

This paper investigates the out-of-equilibrium behavior of ultrasoft particle density profiles under dynamic external potentials using dynamical density functional theory (DDFT), validated by extensive Brownian Dynamics simulations.

Contribution

It demonstrates the accuracy of DDFT with an essentially exact equilibrium free energy functional in predicting density evolution.

Findings

Excellent agreement between DDFT and simulations.

Validates DDFT for out-of-equilibrium ultrasoft particle systems.

Shows the importance of an accurate free energy functional.

Abstract

We examine the out-of-equilibrium dynamical evolution of density profiles of ultrasoft particles under time-varying external confining potentials in three spatial dimensions. The theoretical formalism employed is the dynamical density functional theory (DDFT) of Marini Bettolo Marconi and Tarazona [J. Chem. Phys. {\bf 110}, 8032 (1999)], supplied by an equilibrium excess free energy functional that is essentially exact. We complement our theoretical analysis by carrying out extensive Brownian Dynamics simulations. We find excellent agreement between theory and simulations for the whole time evolution of density profiles, demonstrating thereby the validity of the DDFT when an accurate equilibrium free energy functional is employed.