Ab initio methods were used to study the coordination of electron donors to the (110) and (101) surfaces of a MgCl2 support. The electron donors were alcohols, ketones, esters, and their model compounds. Examination of the interaction energies indicated that the alcohols bind more strongly to the five-coordinated magnesium atom on the (101) surface than to the four-coordinated magnesium atom on the (110) surface. This stability on the (101) surface can be explained in terms of hydrogen bonding between the complexed alcohol and a chloride ion of the surface. Like the alcohols, the esters form the most stable complexes on the (101) surface. In contrast, the ketones coordinate preferably to the (110) surface. The geometries of these coordinated electron donors can be predicted fairly reliably even with small model compounds. In the case of the alcohols, the coordination angle between the donor and the surface depends on the number of alcohols on the same magnesium atom.