Chapter 18 - Universal scaling of binding energies

Abstract

The universality of the binding-energy relation is not limited to the simple metals and to adhesion. The theoretical total cohesive-energy curves calculated for bulk metals as a function of inter-atomic separation can be also scaled into a universal function. The separation among atoms is expressed in terms of the Wigner–Seitz radius. The Thomas–Fermi screening length is determined using the equilibrium interstitial electron density. Universal binding-energy-distance relationship can be found also for the atoms chemisorbed on a metallic surface. The variety of shapes ranging from slowly varying function for low-density alkalis to a relatively strong-varying function for hydrogen, again, can be scaled onto a single universal curve. The chapter explains the resultant universal relations for energy-distance dependence in adhesion, cohesion, and adsorption as well as for diatomic molecules fall to a high degree of accuracy into one universal curve.