Shell Structures in ⁹¹Nb

High spin states of ⁹¹Nb are populated via the fusion−evaporation reaction ⁷⁶Ge (¹⁹F, 4n)⁹¹Nb at the beam energy of 80 MeV. The existing level scheme is modified and extended to higher spins. Its low−lying states are well described by the weakly coupling between a g_9/2 proton and the even−even ⁹⁰Zr core, whereas the higher level structures could be interpreted by the multi−particle excitations in the model space p (1f_5/2,2p_1/2,1g_9/2) n (1g_9/2,2d_5/2,1g_7/2) in the framework of the shell model.