Electronic Structure Calculations for YBa2Cu3O7 within the Slave Boson Formalism.

A novel method for self-consistent electronic structure calculations for correlated metals is presented. This approach takes into account on-site Coulomb repulsion among localized electrons and is based on the slave boson formalism. The proposed method was applied to the study of the electronic structure of YBa{sub 2}Cu{sub 3}O{sub 7}: the on-site Coulomb repulsion of Cu3{ital d} electrons gives origin to a flat band at the Fermi level, as observed in experiments. A sharp Van Hove singularity has been found 25meV below the Fermi energy. {copyright} {ital 1996 The American Physical Society.}