Self‐Consistent MAPW Calculation with a Warped Muffin‐Tin Potential. I. The Electronic Structure of Al and Its Pressure Dependence

Abstract

AbstractIn the framework of the MAPW‐formalism the warped‐muffin‐tin approximation is discussed in detail. It turns out that the usually neglected terms are not only small as a consequence of wellknown facts of electrostatics but that the MAPW‐formalism has the advantage that the dominant multipole densities vanish with zero slope at the surface of the APW sphere. Using this approximation the electronic structure of Al is evaluated at seven different values of the lattice constant. This information enables the determination of the equation of state at zero temperature, the pressure dependence of the shape of the Fermi surface as well as the compressibility. At low pressures the agreement with experiments currently available is considerable. For higher pressures we expect a drastic change of the Fermi surface which should be seen by de Haas‐van Alphen experiments.