SELF-CONSISTENT RELATIVISTIC FULL-POTENTIAL KORRINGA-KOHN-ROSTOKER TOTAL-ENERGY METHOD AND APPLICATIONS

The self-consistent full-potential total-energy Korringa-Kohn-Rostoker electronic-structure method is generalized to include all relativisti c effects. The Dirac equation for a general anisotropic 4 x 4 potentia l is solved inside Voronoi polyhedra surrounding each basis atom. As a n illustration, the method is used to calculate the self-consistent el ectronic band structure, the Fermi surface, the equilibrium lattice co nstant and the bulk modulus of the fee transition metals Pd, Ir, Pr, a nd Au. If the cutoff of the multipole expansions of the wave functions is at least l(max) = 4, the calculated equilibrium lattice constants of the transition metals deviate from experiment by less than 1%, and the calculated bulk moduli deviate between 6% and 20% which is compara ble to results of other local-density calculations. In addition, the m ethod is used to calculate the self-consistent electronic band structu re of the semiconductors GaAs, InSb, and InN, and the equilibrium latt ice constant and the bulk modulus of InSb. We find that the inclusion of both spin-orbit coupling and full-potential effects influences the size of the valence-band-width and the band gap in comparison with sca lar relativistic local-density calculations. interestingly, if after s elf-consistency has been achieved in scalar relativistic calculations, spin-orbit coupling is taken into account by the so-called second var iation, the energy bands are found to agree very well with the results obtained here with the full relativistic treatment.