“…The calculations based on several variants of the shell correction method (123,124,126,206,285,324,364,395,(424)(425)(426)(427)(428) and HF approach (74,429) show the great sensitivity of the model predictions, especially for tran sitional nuclei such as 96,98Zr. The onset of quadrupole deformation around N = 58 can be understood in terms of an interplay between the spherical Z = 40, N = 56, and the deformed Z = 40, N = 60 closures in the single-particle spectrum (206,430) (see also Section 8.1 for more discussion). In order to illustrate the sensitivity of calculated PES in this region to the choice of model parameters, we show in Figure 38 the total energy curves versus /3 2 for 96,98.…”