A method to incorporate the radial distribution function of bulk fluid into the density functional approximation

A systematic methodology is proposed to deal with the weighted density appr oximation version of classical density functional theory by employing the k nowledge of the radial distribution function of bulk fluid. The present met hodology results from the concept of the universality of the free energy de nsity functional combined with test particle method. It is shown that the n ew method is very accurate for the predictions of the density distribution of a hard sphere fluid at different confining geometry. The universality of the present methodology is discussed. (C) 2001 American Institute of Physi cs.