INTERMOLECULAR POTENTIAL FUNCTIONS FOR ADSORPTION IN ZEOLITES - STATE-OF-THE-ART AND EFFECTIVE MODELS

In the simulation of physical adsorption, the adsorbate-adsorbent pote ntial function plays a central role. Much labour is involved in obtain ing a potential function which takes into account two-body and three-b ody dispersion terms in place of a more empirical effective potential, and it is important to enquire whether effective potentials can furni sh an acceptable solution to the problem. Here we review the construct ion of a more elaborate potential function for the interaction of non- polar probes with silicalite and with AlPO4-5, and analyze the contrib utions which arise from the different terms. The possibility of employ ing effective potentials based on the summation of 12-6 or 6-exp funct ions is examined, and it is concluded that no guarantee can be offered for the success of the simplified procedure.