THEORY OF CHEMICAL BONDING BASED ON THE ATOM-HOMOGENEOUS ELECTRON-GAS SYSTEM

We review recent developments in the theory of chemical bonding based upon replacement of an N-atom system by N individual systems each consisting of an atom embedded in a homogeneous electron gas. These theories include the corrected effective medium and effective-medium-based methods, which are either first principle or semi-empirical, as well as the embedded atom and related methods (e.g. the 'glue' and Finnis-Sinclair methods), which are totally empirical. These methods can provide an accurate description of metal-metal interactions for simple or transition metals with weak d bonding, including homogeneous and hetergeneous systems. They also can describe the binding of non-metallic atoms to metals. A number of these methods are efficient enough computationally to be used in molecular dynamics and/or Monte Carlo simulations of systems with many thousands of atoms.