The subshell closure at N = 56 and the deformation of neutron-rich isotopes from Ge to Zr

The microscopic energy density method is applied to the study of nuclei with N ? 50 and Z = 32?40. The experimental Subshell effect at N = 56, which is not found in many previous works about this region, is well reproduced by the present self-consistent calculation. The existence of strongly deformed prolate isotopes of Zr and Sr for N ? 60 is also explained. A wide region of oblate shapes is predicted for N ? 60 and Z ? 36. The results also support the interpretation of low-energy isomers in the shape transition region as shape isomers.