PRECISE BAND-STRUCTURE AND FERMI-SURFACE CALCULATION FOR YBA2CU3O7 - IMPORTANCE OF 3-DIMENSIONAL DISPERSION

With the appearance of angle-resolved photoemission data allowing the identification and measurement of the Fermi surface of the high-Tc cuprate superconductors, it is important to have precise local-density calculations with which to compare. We present well-converged local-density predictions of the band structure and Fermi surface of YBa2Cu3O7, giving special attention to the position of the flat Cu-O chain-derived bands and the effect of the buckling of the Cu-O chain that is predicted by total-energy calculations and that has been inferred by an x-ray-scattering study. We emphasize the c-axis dispersion that will lead to apparent broadening of the Fermi surface in experiments interpreted in terms of a two-dimensional electronic structure. © 1990 The American Physical Society.