First-Principles Electronic Structure Theory for Semi-infinite Semiconductors with Applications to Ge(001) (2×1) and Si(001) (2×1)

The electronic structure of semi-infinite semiconductors with energy-optimized reconstructed surfaces is calculated self-consistently for the first time. Using local-density-functional formalism and scattering theory, the calculations yield the potential, charge density, surface band structure, and wave-vector-resolved layer densities of states with extreme spectral resolution. The results quantitatively explain recent surface spectroscopy data on occupied and empty states for Ge(001) (2×{}1) and Si(001) (2×{}1).