EMBEDDED-CLUSTER STUDY OF WATER-ADSORPTION AT CR2O3(0001)

Quantum chemical calculations on the molecular and dissociative adsorp tion of water at the Cr2O3(0001) surface are performed. A specially pa rametrized version of the semi-empirical SCF MO method SINDO1 is used for the calculations. The surfaces are simulated with model clusters e mbedded in finite arrays of pseudo-atoms, Different possible surface t erminations are taken into account and their adsorption behaviour is c ompared. Single-molecule adsorption is studied as well as monolayer ad sorption. A comparison of the calculated results for the relative stab ilities of molecular and dissociative adsorption, dissociation barrier s. electronic structures and adsorption geometries of water with exper imental data leads to conclusions for the most probable surface termin ation of Cr2O3(0001). (C) 1998 Elsevier Science B.V. All rights reserv ed.