Complex nuclear spectra in a large scale shell model approach

We report on a shell model implementation of an iterative matrix diagonalization algorithm in the spin uncoupled scheme. A new importance sampling is adopted which brings the eigenvalues to convergence with about 10% of the basis states. The method is shown to be able to provide an exhaustive description of the low-energy spectroscopic properties of 132-134Xe isotopes and of the spectrum of 130Xe.