THEORETICAL INVESTIGATIONS ON ADSORPTION AT ION CRYSTAL-SURFACES

Experimental and theoretical methods for the study of adsorption at ion crystal surfaces are reviewed. New SINDO1 calculations on surface-adsorbate systems are presented in this framework. The special surface systems NaCl, MgO and TiO2 are selected to demonstrate the feasibility of current molecular orbital methods for the generation of surfaces and the study of adsorption of small molecules exemplified by CO2 and H2O. Molecular and dissociative adsorption can be distinguished in the case of adsorbed H2O. A scheme is presented for the systematic improvement of the results. Trends are discussed for geometry, binding characteristics, energetics and infrared spectra of adsorbed molecules. The calculated properties are compared with experimental data.