Static Quadrupole Moment of the First2+State of Vibrational Nuclei

It is shown that reasonable models of vibrational nuclei can be constructed that explain the large magnitude of the static quadrupole moment $Q_2$ of the first excited $2^{+}$ state of ${}_{}{}^{114}{}_{}{}^{}\mathrm{Cd}$, recently derived from the analyses of the Coulomb-excitation experiments. Since the models considered are kept in very simplified forms, in order to make their qualitative implications as transparent as possible, they do not necessarily explain all the other known properties in this nucleus. Nevertheless, it seems that there is room for improving these models while still predicting large $Q_2$, and thus it is concluded that one can continue to consider ${}_{}{}^{114}{}_{}{}^{}\mathrm{Cd}$ as a vibrational nucleus, and not a rotational nucleus, in spite of the large magnitude of $Q_2$.