Applicability of the extended P+QQ model in the upper part of the f7/2 shell

The P-o + P-2 + QQ force has been completely revised, and in its new form, it is capable of describing nuclear structure of N approximate to Z nuclei well. This paper investigates the applicability of the extended P+QQ model in the upper part of the f(7/2) shell using shell model calculations. It is shown that the extended P + QQ model can account for the collective bands of most 52 less than or equal to A less than or equal to 56 nuclei as well as the lower part Of the f(7/2) shell. However, considerable discrepancy with experiment exists for Fe-52, which suggests the limit of the applicability of this force.