A simple method for calculating the corrugation of metal surfaces

We present a simple method to introduce corrugation into jellium-type model s for metal surfaces. As our reference we take a one-dimensional system tha t is homogeneous parallel to the surface, and expand the density functional in the three-dimensional correction. By choosing a suitable family of tria l functions we calculate the corrugation up to second order in the perturba tion. Our results compare well with calculations based on a full three-dime nsional treatment. An application to charged surfaces suggests that the ele ctronic corrugation is larger for a positively than for a negatively charge d surface. Our method should be particularly useful in the modeling of comp lex interfaces. (C) 1999 Elsevier Science B.V. All rights reserved.