Density profiles and pair correlation functions of hard spheres in narrow slits

摘要

A hard sphere fluid confined by hard, structureless, and parallel walls isinvestigated using a certain version of weighted density functional theory. Thedensity profile, the excess coverage, the finite size contribution to the freeenergy, the solvation force, and the total correlation function are determinedas function of the slit width $L$ for various bulk number densities $\rho_b$.In quantitative agreement with rigorous results the present version of densityfunctional theory yields a constant and large but finite number density profilefor the limiting case that $L$ is reduced to the diameter of the hard spheres.Within the Derjaguin approximation the results for the slit geometry allows usto obtain the solvation force between two large hard spheres immersed into afluid of much smaller hard spheres.