  The single-particle spectrum of the two nuclei 133Sb and 101Sn is studied
within the framework of the time-dependent degenerate linked-diagram
perturbation theory starting from a class of onshell-equivalent realistic
nucleon-nucleon potentials. These potentials are derived from the CD-Bonn
interaction by using the so-called V-low-k approach with various cutoff
momenta. The results obtained evidence the crucial role of short-range
correlations in producing the correct 2s1d0g0h shell structure.
