Relativistic optimized effective potential method—application to alkali metals

Abstract

We present a relativistic formulation of the optimized effective potential method (ROEP)and its implementation within the Korringa–Kohn–Rostoker multiple scattering formalism.The scheme is an all-electron approach, treating core and band states formally onthe same footing. We use exact exchange (EXX) as an approximation to theexchange correlation functional. Numerical four-component wavefunctions for thedescription of core and valence electrons and the corresponding ingredients ofthe ROEP integral equation are employed. The exact exchange expression forthe valence states is reformulated in terms of the electronic Green’s functionthat in turn is evaluated by making use of multiple scattering formalism. Wepresent and discuss the application of the formalism to non-magnetic alkali metals.