©North-Holland Publishing Company m~t9as STRENGTH OF THE Q ~ Qd INTERACTION AND

Abeh~act: The suitability of pseudo SU(3) strong coupled wave functions in representing the normal parity part of yrast eigenstates of systems with protons and neutrons filling diJfercnt major shells and interacting with one another via a Q " Q interaction is explored. In addition, we find that the overlaps of yrast eigenstates of H with the leading SU(3) symmetry follow the correlation of Q " Qwith H very closely and are large even when Q ~ " Q contributes less than half to the full width of the eigenvalue spectrum of H. The results suggestthat the pseudo-SU(3) coupling scheme will prove useful in microscopic shell-model studies of high-spin phenomena in rare earth and actinide nuclei. 1. Introdnctlon A theoretical interpretation of high-spin and related phenomena in heavy de-formed nuclei, where the number of spectroscopically active nucleons is large, has come about mainly through phenomenological quasiparticle-plus-rotor studies or through more microscopic Hartree-Fock-Bogoliubov mean field theories. The advantage of a fully microscopic approach hasrecently ledus toproposeashell-model theoryforhigh-spinphenomena. Thenecessarilyseverebasis truncation is effectedb