  We have performed shell-model calculations starting from the CD-Bonn free
nucleon-nucleon NN potential and making use of a new approach for the
calculation of the effective interaction. This consists in deriving from the NN
potential a low-momentum effective potential V-low-k, defined within a given
cut-off momentum Lambda. Being a smooth potential it can be used directly in
nuclear structure calculations. To assess the practical value of this approach,
we have also performed calculations within the framework of the usual Brueckner
G-matrix formalism. Comparison of the calculated results between them and with
the experimental data shows that the V-low-k approach represents an
advantageous alternative to the use of the G-matrix.
