EfFective interactions for the OplsOd nuclear shell - madel space

Shell-model interactions are constructed in the cross-shell model space connecting the Op and ls0d shells with due regard for the perturbative efFects of the neighboring Os and Oflp shells. The interactions have three distinctive Op-shell, cross-shell, and 1sOd-shell parts. The latter is taken to be the previously determined W interaction. The Op-shell interaction is represented by two-body matrix elements and the cross-shell by either a potential or by two-body matrix elements. The interactions are determined by least-squares fits to 51 Oy-shell and 165 cross-shell binding energies. It is found that the addition of monopole terms to a potential that is otherwise similar to that of the Millener-Kurath interaction results in a great improvement in the fit. In the fit to two-body matrix elements, 45 of 97 possible linear combinations of parameters are varied and the root-mean-square deviation for the 165 cross-shell energies is 330 keV. Examples of the application of the interactions are given for the prediction of neutron-rich binding energies, Gamow-Teller decays, and 0~, 1h~,