Electrostatic Model Calculations On Multiple Adsorption At Nacl Surfaces

A previously proposed electrostatic model for physisorption at ionic solids is extended to multiple adsorption of small molecules. A new algorithm is developed to avoid interpenetration of the interacting systems. The geometry optimization procedure is described. Ab initio calculations are used for the application of the method to the adsorption of CO and CO2 at NaCl(100) surfaces simulated by Na25Cl25 clusters. The orientation of the adsorbate molecules in dependence on the cumulative atomic multipole moments (CAMMs) of the cluster atoms is discussed. (C) 1997 John Wiley & Sons, Inc.