  Within the BCS framework a multiband model with d-wave symmetry is
considered. Generalized Fermi surface topologies via band overlapping are
introduced. The band overlap scale is of the order of the Debye energy. The
order parameters and the pairing have d-wave symmetry. Experimental values
reported for the critical temperatures $T_c(x)$ and the order parameters,
$\Delta_0(x)$, in terms of dopping $x$ are used. Numerical results for the
coupling and the band overlapping parameters in terms of the doping are
obtained for the cuprate superconductor $La_{2-x}Sr_xCuO_4$.
