On a more exact treatment of the conduction electron potential in first principles calculations of lattice dynamics of metals

Abstract

Reports the use of a more complete and exact treatment of the conduction electron potential in Harrison's first principle non-local pseudopotential formalism for the calculation of phonon spectra of both BCC and HCP metals. The resulting phonon dispersion curves exhibit improved agreement when compared to calculations using Harrison's original approximate treatment of the conduction electron potential. It is found that the improved results are attributable to not only the used of the exact conduction electron potential but also to the use of the proper core-energy eigenvalues, i.e., the experimental values, in the expression for the crystal potential matrix element.