First-principles calculation of energy of an epitaxial system

A self-consistent pseudopotential calculation of the energetics of aluminum growth on Ge(001) in the epitaxial relationship (001) [100] $\mathrm{}\left(001\right)\mathrm{}\left[100\right]\mathrm{}\mathrm{A}1\mathrm{}\parallel \mathrm{}\left(001\right)\mathrm{}\left[110\right]\mathrm{}\mathrm{Ge}$ is presented. We observe that the equilibrium Al-Ge interplanar distance increases with the overgrowth thickness $t$ and, more significantly, rapidly saturates ($t\lesssim 3$) to a value equal to the average interplanar distances of the two systems. We also conclude that the Frank-van der Merwe growth sequence of Al would begin at the bridging sites on Ge(001).