PLANAR-BASIS PSEUDOPOTENTIAL CALCULATIONS OF THE SI(001)2X1 SURFACE WITH AND WITHOUT HYDROGEN PASSIVATION

A planar basis is introduced for self-consistent pseudopotential calculations. The basis is made of products of two-dimensional plane waves (in x-y plane) and Gaussian functions in the z direction. This basis is particularly suited for describing electronic states of heterostructures including surfaces, interfaces, and superlattices. The method is applied to the Si(001)2 x 1 surface with symmetric dimer reconstruction and the effects of hydrogen passivation are studied. The work function and dissociation energy of hydrogen from the Si(001)2 x 1 surface are calculated. The results for hydrogen dissociation are in agreement with previous experimental findings.