[en] Research under this continuing DOE contract centers on radioactive decay studies of nuclei far from stability produced with heavy ions from the Holifield Heavy Ion Research Facility (HHIRF) and studied on-line with the University Isotope Separator at Oak Ridge (UNISOR). These investigations encompass three aspects of nuclear structure research: nuclear spectroscopic measurements involving detailed γγt, γe^-t, and Xγt three-parameter coincidence spectrometry; on-line laser hyperfine structure (hfs) and isotope shift spectroscopy for determining quadrupole moments, nuclear spins, and mean nuclear charge radii; and computer calculations of nuclear model predictions for comparison with the experimental level schemes. The focus of this research program is on odd-mass nuclei in which the odd nucleon probes the core, making possible observation of such phenomena as the onset of abrupt shape changes, the occurrence of shape coexistence, and shell-model intruder states. These phenomena are critical tests of concepts fundamental to an understanding of low-energy nuclear structure, such as nuclear deformations, shell models, collective models, and particle-core couplings