Deep Inelastic Scattering of Electrons
http://hyperphysics.phy-astr.gsu.edu/hbase/Nuclear/scatele.html#c1For the first time, physicists have clearly observed a rare and complex motion of atomic nuclei called longitudinal wobbling -- in an excited state, some nuclei with an odd number of nucleons exhibit a complex wobbl like that of a spinning top because of their imbalanced geometry. : science
https://www.reddit.com/r/science/comments/fcb4sb/for_the_first_time_physicists_have_clearly/Semi-empirical mass formula - Wikipedia
https://en.wikipedia.org/wiki/Semi-empirical_mass_formula