The structure of the ground states of nickel isotopes and the effective interactions in the 2p-1f shell

The HFB calculations are carried out for the even-even Ni isotopes, employing the Kuo-Brown effective interaction for the 2p-1f shell, modified slightly so as to satisfy certain constraints imposed on it by the BE2(0 → 2) systematics in the shell. Quite contrary to the results obtained in some earlier calculations, the conventional approach of assuming 1 f 7 2 sub-shell closure for protons as well as neutrons is seen to be valid to a good extent for Ni isotopes.