Realistic Effective Interactions and Large-Scale Nuclear Structure Calculation

We describe the properties of complex nuclei, such as the Sn isotopes with mass numbers A = 100 - 132, in terms of the free nucleon--nucleon interaction as obtained from meson--exchange theory. This amounts to first calculating an effective interaction in which the free interaction is modified by the presence of the appropriate nuclear medium. The short--range correlations are included within the framework of Brueckner theory yielding the nuclear reaction matrix and the long--range correlations by using the reaction matrix in many--body perturbation theory to obtain an effective interaction. The resulting effective interaction is then employed in calculating the nuclear properties. Particular emphasis is placed on the ability of our calculation to describe systematic trends of the properties of these nuclei. Both successful achievements and problematic features are pointed out.