Unified analysis of static, dynamic and electronic properties of the alkali metals

The realization of Harrison's first-principles pseudopotential concept is re-analyzed. It is shown that the most critical and at the same time most fundamental step is the separation of the electronic system into two subsystems, tightly-bound core-electrons and quasi-free valence-electrons. Different varieties of the local statistical Xα-exchange and correlation approximation are used to describe the core-core and valence-core many-body interactions. Many-body effects among the conduction-electrons are taken into account by using different modified forms of the dielectric screening function. The different potentials are applied to a calculation of phonon-dispersion relations and mode-Grueneisen parameters, of the cohesive properties (equilibrium lattice constant, binding energy, compressibility, equation of state), of the crystal structure, the thermodynamic properties, the interionic pair potential and of some electronic properties (liquid resistivity as a function of temperature, Fermi-surface data). It is shown that a careful description of the many-body interactions, both in the formulation of the electron-ion potential and in the screening process, allows a quantitatively accurate unified and fundamental analysis of a wide range of different properties. (orig.)