Influence of Conduction-Band—Core Electron Exchange and Correlation on Pseudopotential Calculations

Abstract

Using the Harrison first-principles nonlocal pseudopotential theory, an investigation was made to determine the influence of conduction-band-core electron exchange and correlation in the phonon dispersion relations in metallic lithium. The results of this study, together with previous results for the simple hcp divalent metals, indicate that (i) the phonon spectrum is extremely sensitive to the choice of an effective potential to approximate this interaction, and (ii) there is still no single a priori "best" choice for this approximation.