1ST-PRINCIPLES CALCULATION OF THE DISPERSION-RELATIONS FOR ZN

In case of Zn, the application of the Heine-Abarenkov (HA) model potential in the local approximation gives unstable dispersion results. Computed dispersion curves are seen to be comparable to neutron data only when the nonlocal effects in Zn are taken into account. However, earlier model-potential calculations are not satisfactory because of either the prediction of unstable dispersion results or the use of adjustable nonlocal parameters. In the present work, the nonlocality of the HA model potential is considered and, without using any adjustable parameter, we get stable phonon dispersion results for Zn which compare reasonably well with the neutron data of Almqvist and Stedman. © 1979 The American Physical Society.