Ground-state properties of GaAs and AlAs

Ground-state properties of GaAs and AlAs are studied and compared using the self-consistent pseudopotential method. The calculated equilibrium lattice constant, the bulk modulus, and the cohesive energy of these compounds are in good agreement with experiment. This agreement allows for the investigation of a subtle difference in the bond strength between GaAs and AlAs. The density of states for the two compounds is found to be similar, but there exists a characteristic difference which can be used as a sensitive probe for distinguishing different species. The valence charge density and the kinetic energy density functions for these compounds are illustrated for comparison.