Electronic properties of liquid metals and alloys calculated with the first-principles model (pseudo)potential of Bachelet, Hamann and Schluter: the Ga-Ge system

Abstract

A model (pseudo)potential method has proven to be an interesting technique for calculating electronic properties in the framework of the Ziman formula for pure liquid metals and the Faber-Ziman expression for liquid alloys. First-principles model potentials are non-local and their parameters are energy dependent. In the alloy one must take into account an energy dependent effective mass, a depletion hole and the Fermi energy core shift which is not known for alloys. Furthermore, the thermopower explicitly includes an energy dependent contribution. The first-principles model (pseudo)potential of Bachelet, Hamann and Schluter (BHS) is energy independent and avoids the necessity of making these corrections (see Phys. Per. B, vol.26, p.4199, 1982). It has been used to calculate analytically the corresponding form factor. The resistivity and the thermopower of pure germanium and gallium and of the germanium-gallium alloy have been determined by using the Faber-Ziman formalism. Both hard sphere and experimental structure factors have been used (when available). The agreement between experimental and theoretical properties can be considered as good and confirms that the BHS model potential is adequate for describing the electronic properties of liquid alloys.