Modern shell-model diagonalizations with realistic NN forces

The spectral and statistical properties of nuclei $^{46}$V and $^{48}$Cr are studied in the framework of nuclear shell model. A microscopical effective Hamiltonian derived from the CD-Bonn \textit{NN} potential is employed. The calculations are preliminary results of a newly developed parallel shell-model code. Calculations with the realistic \textit{NN} interaction reproduce well the ground-state rotational band and backbending phenomenon in $^{48}$Cr. A sudden alignment of all particles is seen above the backbend. The nearest-neighbour spacing distribution in $^{46}$V is presented and compared with the predictions of random-matrix theory. Significant deviation from the single Gaussian-orthogonal-ensemble distribution is obtained, indicating that the isospin-symmetry breaking is not so strong in the nucleus.