ALIGNMENTS AND SHAPE CHANGES IN SE-77

High-spin states in Se-77 were studied using the Ge-76(alpha,3n) react ion at 40 MeV at the Florida State University Tandem-LINAC facility. P rompt gamma-gamma coincidences were observed using the Pitt-FSU detect or array. The positive- and negative-parity yrast bands were extended up to spins of (31/2(+)) and (27/2(-)), respectively. Spin assignments were made based on directional correlation of oriented nuclei ratios whenever possible. A rich and complicated high-lying high-K negative-p arity structure was also found. The positive-parity yrast structure sh ows a change from large signature splitting at low spin to a more unif orm level spacing at higher spins, as has been seen in the heavier N=4 3 isotones. Theoretically, this change is attributed to a shift from o blate to triaxial shape due to the alignment of a pair of g(9/2) proto ns.