SELF-CONSISTENT RELATIVISTIC LINEAR AUGMENTED PLANE-WAVE METHOD - APPLICATION TO YBGA2

In order to derive an efficient method for calculating the electronic structures including the f bands in the rare-earth and the actinide compounds with complex crystal structures, Loucks' relativistic augmented-plane-wave method is converted into a linear form by relativistic band theory proposed by Takeda. In this method, the four-component relativistic plane wave is augmented by a linear combination of the solutions of the Dirac equation for two fixed energies for each angular momentum, and the secular equation is derived directly from the Dirac Hamiltonian. As an application of this linear method, the electronic structure is calculated for the double-hexagonal rare-earth compound YbGa2. A self-consistent calculation reveals that the f bands lie just below the Fermi level and that the Fermi surface consists of small hole and electron sheets, which can explain experimental results for the de Haas-van Alphen effect reasonably well.