First-Principles Pseudopotential Total-Energy Calculations for Elemental, Compound and Alloy Semiconductors

The first-principles pseudopotential total-energy calculation within the local density functional formalism has been performed for several types of semiconductors: Si, GaAs, AlAs and Al x Ga 1- x As. The calculated lattice constant, bulk modulus, cohesive energy and the overall energy-band structure are in excellent agreement with the experimental data. Both the hard core and the soft core pseudopotentials are constructed from the first principles, and their validities are examined through the detailed calculations with the full converged plane-wave basis set. Further, the localized-orbital basis set is also introduced and is shown to give quantitative results. In particular, the electronic structure and the ground-state properties of GaAs under hydrostatic pressure are investigated with use of the localized-orbital basis set.