Density Functional Theory of Metal Surfaces

Abstract

One of the main themes of this volume is the sensitivity of electronic excitations at metal surfaces to the ground-state electronic properties in the surface region and to the nonlocal response of surface electrons to incident electromagnetic fields. The density functional approach provides an accurate description of both properties. Since this scheme forms the theoretical basis for nearly all linear and nonlinear electronic excitations treated in the following chapters, we describe here the salient aspects of this approach. Section 1 deals with ground-state properties. We introduce the local density approximation and the jellium model for which most calculations have so far been performed. We also discuss the so-called stabilized jellium model that takes the electron—ion interaction into account in a better way than the standard jellium model. The static response properties of jellium surfaces are presented for both models. The time-dependent extension of the density functional method is the topic of Section 2. We focus on the adiabatic treatment of the induced exchange-correlation potential, but we also mention recent dynamical generalizations. An important feature is the description of some of the computational procedures for evaluating surface response properties; these are presented in Section 3. We give the expressions of relevant quantities and point out the necessary steps that allow a stable and accurate calculation of induced dipole moments; additional aspects are pointed out in other chapters.