Mass-surface predictions near the doubly magic nuclide Ni-78

The mass surface of nuclei close to the doubly magic nuclide Ni-78 is calcu lated by two methods. The first relies on the multiparticle shell model bas ed on an effective interaction and a mean nuclear potential. The second emp loys the concept of so-called "magic crosses" and enables us to determine t he masses of odd-odd nuclei close to Ni-78 by using similarity of the shell structure and neutron-proton interaction in the region of nuclei under con sideration and in the region of heavy magic nuclides. The energies of the s eparation of one and two neutrons from nuclei close to Ni-78 and the energi es of the beta decay of these nuclei-recall that these quantities of astrop hysical interest-are presented. (C) 2000 MAIK "Nauka/Interperiodica".