Study of the reconstructed GaAs(100) surface

The reconstruction of an As-terminated GaAs(100) surface has been studied using the self-consistent pseudopotential method. Total energies for the (1 × 1) ideal surface and the $c(2\mathrm{}\times 2)$ and $p(2\mathrm{}\times 2)$ reconstructed surfaces within the dimer model are compared. Unlike the Si(100) surface, at least two inequivalent dimers are required to produce the semiconducting surface and stabilize the system. Important features in the density of states and the valence-charge distribution are presented.