Electronic Structure and Reactivity of the FS(H)+ Defect Center at the MgO(001) Surface

FS(H)+ centers at the (001) surface of MgO have been characterized in terms of electronic structure, magnetic properties, and chemical reactivity toward adsorption of O2 and N2 molecules by means of cluster model density functional calculations. Two different arrangements of the OH group on the surface have been considered: the computed properties are in excellent agreement with observed EPR and IR data and show the existence of important analogies between the two arrangements, but also of some significant differences. At short distances from the surface, a transfer of the trapped electron from the surface to the admolecules occurs, with formation of charge-transfer complexes.