Computer modeling techniques provide a useful mechanism with which to model the morphology of defect crystals. In this work, a study of the incorporation of sodium and potassium cations into the morphologically important surfaces of gibbsite was conducted. Computation of the resulting changes in surfaces energies was achieved with the aid of a Born-Haber cycle. These calculations were then employed to determine the defect influenced morphologies for both cations. The resulting habits suggest that cation incorporation contributes to the elongation of the prismatic faces and also to the formation of diamond morphologies.