Experimental Techniques Used to Obtain Potentials

Abstract

The electrons in a metal or alloy may be divided into two types: the core electrons which are tightly bound within the atom and the conduction electrons which are relatively loosely bound and which are responsible for most of the characteristic properties of the metallic state. The aim of the pseudopotential method is to transform the equation

$$[T + V(r)]{\psi _k} = {E_k}{\psi _k}$$

((1))

into

$$H{\phi _k} = {E_k}{\phi _k}$$

((2))

where T is the kinetic energy operator, V the (Hartree) potential, and ø _k is a smooth wave function that has none of the violent oscillations close to the nucleus which characterize ψ _k , the set of conduction electron wave functions. It turns out that this transformation may be accomplished provided the new operator is written H = T + W(r, k) where W(r, k) is a pseudopotential.