Total Energies and Atom Locations at Solid Surfaces

Abstract

With the advent of modern computers it is now possible to compute total energies at surfaces from first principles. However, the kinds of problems that can currently be dealt with are quite restrictive. A brief overview of such calculations, as well as the recently discovered universality in binding energy relations will be given. We show that it is now possible to calculate surface or cleavage energies of transition metals from first principles. This is done via our self-consistent local orbital (SCLO) method. The total energies of metal films of many thicknesses, for example of three, five, seven, and nine layers, are first computed; a bulk and surface energy are then derived from a least-squares linear plot of total energy versus film thickness. In the examples of copper(100) and silver(100), the deviation from the line is less than 0.1 eV. This shows the accuracy of our method since the slope of the line (the bulk energy) is four Orders of magnitude larger than the intercept (twice the surface energy). Good agreement with experiment is obtained for all metals considered.