Electronic structure of metals. I. Energy independent model pseudopotential formalism

An energy independent model pseudopotential formalism for calculating the electronic structure of metals is developed so that uncertainties in the determination of the model potential parameters, such as those occurring in the Heine-Abarenkov type model potential due to the energy dependence, can be avoided. A model potential, in general more suitable than the square-well potential, with parameters determined by fitting to the energy levels of the low-lying atomic valence states is presented and is used in the construction of the model pseudopotential for the applications to metals. An expression for the form factor, including the effective mass and exchange-correlation effects, is derived in a way consistent with the proposed model pseudopotential.