Effect of structural considerations on the development of free energy functionals for the square-well fluid

Thomas Bernet , Manuel Pineiro (1) , Frédéric Plantier (2) , Christelle Miqueu (2)

1 Department of Applied Physics
2 TEFC - Thermodynamique et Energétique des fluides complexes

In this work, we compare four inhomogeneous square-well fluid models, only distinct in the approximation on the pair correlation function present in the attractive free energy term of the density functional theory (DFT). Various criteria can be considered to select or validate an approximation, depending on fundamental interests or for a specified application. Here the considered criteria of selection were the verification of sum rules, and the prediction of both the adsorbed quantity and the density profiles. Even if a model satisfies one of these criteria, it may fail to describe others, so they can be considered supplementary to each other and in no case redundant. According to this study, one can attach more importance to any of these criteria depending on the specific objectives intended for the model development and purpose. They can serve as references in the development of new DFT models, eventually with other criteria, according to the objective of the work and the accuracy desired.

Mots clés: Density functional theory; fundamental-measure theory; pair correlation function; coarse-graining; mean-field

Domaines: Physique [physics]; Sciences de l'ingénieur [physics]; Chimie théorique et/ou physique

Thomas Bernet, Manuel Pineiro, Frédéric Plantier, Christelle Miqueu. Effect of structural considerations on the development of free energy functionals for the square-well fluid. Molecular Physics, 2018, 116 (15-16), pp.1977-1989. ⟨10.1080/00268976.2018.1438677⟩. ⟨hal-02013246⟩