FIGURE 1.1 Various shapes of nuclei either observed or expected. Exotic orbitals that appear in regions far from the stability line may provide some new types of deformation. The superdeformation and octupole pear-shaped deformation (bottom) have been observed experimentally. The oblate superdeformation has been predicted but not observed—less-deformed oblate shapes are, however, quite common. The hyperdeformation has been seen in certain nuclei. The octupole banana-type deformation has not been observed in such extreme form, but vibrations of this kind are well known. Reprinted with permission from Report of the Study Group on Radioactive Nuclear Beams to the OECD Megascience Forum Working Group on Nuclear Physics, copyright 1998 OECD.