A NEW INTERPRETATION OF THE STICKY HARD-SPHERE MODEL

The basic results of the sticky hard sphere model are derived using a perturbative solution of the factorized form of the Ornstein-Zernike equation and the Percus-Yevick closure relation. The perturbation parameter is DELTA/(sigma + DELTA), where DELTA and sigma are, respectively, the width of the attractive square well pair potential and the hard core diameter. This derivation leads naturally to an expression for the stickiness parameter, different from the one conventionally used, without invoking the concept of an infinitely deep potential. The theoretical structure factor is compared with two sets of Monte Carlo simulation data and excellent agreement is observed in both cases without the scaling of the square well potential suggested in literature.