Abstract
A method of obtaining a local bare-electron-ion pseudopotential from the phonon dispersion curves is proposed. The major assumption made is that the bare-electron-ion plus the ion-ion interactions can be represented by short-range two-body force constants. This allows the coefficients of any appropriate series expansion for the bare-electron-ion potential to be found in terms of the force constants, the values of which are then determined by a least-squares fit to the phonon dispersion curves. It is hoped that this method can reproduce the phonon dispersion curves more accurately, using fewer parameters than current methods. It may also be used to reveal whether different formulations of the dielectric function are correct, and the pseudopotential may enable accurate calculations of other material properties. The preliminary application, reproducing the phonon dispersion curves of potassium, is presented and is found to be quite encouraging.