Tensorial density functional theory for non-spherical hard-body fluids.

Area of Science:

• Statistical Mechanics
• Soft Matter Physics
• Thermodynamics

Background:

• Existing fundamental measure theories struggle with non-spherical particles.
• Accurate free energy functionals are crucial for understanding fluid phase behavior.

Purpose of the Study:

• To construct and detail a new free energy functional for inhomogeneous hard-body fluids.
• To improve upon Rosenfeld's fundamental measure theory for non-spherical particles.
• To extend the functional's applicability to non-isotropic particle distributions.

Main Methods:

• Construction of a novel free energy functional.
• Application of the functional to hard-spherocylinder fluids.
• Introduction and extension of the ζ correction.
• Comparison with Monte Carlo simulations and virial expansions.

Main Results:

• The new functional yields the isotropic-nematic transition for hard spherocylinders.
• Improved description of inhomogeneous isotropic fluids compared to simulations.
• The extended ζ correction enhances the isotropic-nematic bulk phase diagram prediction.
• The functional shows deviations from the exact second-order virial expansion.

Conclusions:

• The developed functional offers a significant improvement for hard-spherocylinder systems.
• The extended ζ correction is beneficial for non-isotropic systems.
• Further complexity from higher-order tensorial densities may not be justified.