Large-basis shell model studies of light nuclei with a multivalued G-matrix effective interaction.

Large-basis shell model studies of low-lying excitations in light nuclei from He to Li have been performed with a multivalued G-matrix effective interaction, as recently suggested by Haxton et al.. Calculations were performed relative to the vacuum (“no core”) using very large, separable model spaces containing all excitations with unperturbed energies up to 8h̄Ω. Using G matrices derived from a new Nijmegen potential, we achieve a very satisfactory description of these excitations.