  We define the "quadrupole ratio" r_{Q}=\dfrac{Q_{0}(S)}{Q_{0}(B)} where
Q_{0}(S) is the intrinsic quadrupole moment obtained from the static quadrupole
moment of the 2_{1}^{+} state of an even-even nucleus and Q_{0}(B) the
intrinsic quadrupole moment obtained from B(E2)_{0\rightarrow2} . In both cases
we assume a simple rotational formula connecting the rotating frame to the
laboratory frame. The quantity r_{Q} would be one if the rotational model were
perfect and the energy ratio E(4)/E(2) would be 10/3. In the simple vibrational
model, r_{Q} would be zero and E(4)/E(2) would be two. There are some regions
where the rotational limit is almost met and fewer where the vibrational limit
is also almost met. For most cases, however, it is between these two limits,
i.e. 0<|r_{Q}|<1 . There are a few cases where r_{Q} is bigger than one,
especially for light nuclei. In most cases the quadrupole ratio is positive but
there are two regions with negative ratios. The first case is that of light
nuclei and the second has certain nuclei close to ^{208} Pb.

Nuclear Theory;Nuclear Experiment