## Structural properties of fluids interacting via piece-wise constant potentials with a hard core    [PDF]

Andrés Santos, Santos B. Yuste, Mariano López de Haro, Mariana Bárcenas, Pedro Orea
The structural properties of fluids whose molecules interact via potentials with a hard core plus two piece-wise constant sections of different widths and heights are presented. These follow from the more general development previously introduced for potentials with a hard core plus $n$ piece-wise constant sections [Condens. Matter Phys. {\bf 15}, 23602 (2012)] in which use was made of a semi-analytic rational-function approximation method. The results of illustrative cases comprising eight different combinations of wells and shoulders are compared both with simulation data and with those that follow from the numerical solution of the Percus-Yevick and hypernetted-chain integral equations. It is found that the rational-function approximation predicts a more accurate radial distribution function than the Percus-Yevick theory in all the cases and is comparable to or superior than the hypernetted-chain theory in most of the cases.
View original: http://arxiv.org/abs/1304.3817