  The three-band Emery model is applied to study the selected principal
features of the $d$-$wave$ superconducting phase in the copper-based compounds.
The electron-electron correlations are taken into account by the use of the
diagrammatic expansion of the Guztwiller wave function (DE-GWF) method. The
nodal Fermi velocity, Fermi momentum and effective mass are all determined in
the paired state and show relatively good agreement with the available
experimental data, as well as with the corresponding single-band calculations.
Additionally, the influence of the next-nearest neighbor oxygen-oxygen hopping
and intersite Coulomb repulsion terms on the superconducting phase is analyzed.
