Electronic structure calculations have been carried out for various model AlnX clusters with X an atom of an element known, or likely, to give rise to changes in the corrosion resistance of AIX alloys. The calculations involved the use of a novel orthogonal outer-sphere MSX alpha technique and results for the partial densities of states for the clusters Al-50, Al(49)ln, Al49Zn, Al49Cr, Al49Ti, and Al49Ta are consistent with the hypothesis that activation of aluminum is to be expected for dopant atoms with filled d orbitals, giving rise to Friedel states at the surface, while passivation is to be expected when the d-band density is distributed about the cluster Fermi level.