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Using the 2~ 3n) reaction with e-particles of about 40 MeV, we have proved by applying nowadays conventional y-ray spectroscopy in-beam technique, that there are two isomeric states in 2~ at the excitation energies 5,161.3 and 3,195.5 keV having the half-lives 71 ___ 3 and 217_+ 5 ns, respectively. These isomeric states have spins and parities 33/2 + and 25/2-and are mainly due to the i{3~2and .-2 -1 113,2 Pl, 2 configurations, respectively. This conclusion is supported by the experimental g-factors of these states being -0.159_+ 0.008 and -0.0676_+0.0011, respectively. It is furthermore shown that the E2 effective neutron charge is the same for E2 transitions from the 33/2 + state in 2~and from the 12 + state in 2~as required by the assumption that the 2~ core is responsible for the total E2 strength of the neutron holes, and that these states are due to the ii-332 and i-2 configura-13:2 tions. The calculated B(E3) values of E3 transitions from isomeric states in 2~ and 2~ agree reasonably well with the experimental values as expected from the assumption that the E3-strength should come from particle coupling to the octupole states of the 2~ core. The energies of the six most well established excited states in 2~ with angular momenta in the region 19/2-33/2 were calculated using empirical single-particle energies, empirical two-particle interactions and angular momentum algebra. The average deviation between experimental and calculated energies is -3 keV and the root mean square deviation 6 keV as compared to the uncertainty _+ 5 keV in the nuclear masses used in the calculation. For the orbits concerned the shell model is thus valid with an extremely high precision. The contribution of effective three-particle interaction in these orbits must consequently be less than about 5 keV.

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