Chemisorption of H on GaAs(110): a first-principle calculation.

We calculate the equilibrium structure of a monolayer of H chemisorbed on GaAs(110), and show that is characterized by the full removal of the substrate relaxation and by a counterrelaxation of about -5 degrees.The corresponding vibration frequencies of the H-subtrate bonds and chemisorption induced changes in the electronic structure are also calculated, and found in good agreementwith the available experimental data.