With Wigner’s SU(4) supermultiplet symmetry [and its generalization to pseudo-SU(4)] as a starting point, a boson-model space is constructed that includes $T=0\mathrm{}$ as well as $T=1\mathrm{}$ bosons (interacting boson model-4). The boson Hamiltonian is derived microscopically from a realistic shell-model interaction through a mapping that relies on the existence of approximate shell-model symmetries. Applications are presented for odd-odd $N=Z$ nuclei from ${}_{29}^{58}{\mathrm{Cu}}_{29}$ to ${}_{35}^{70}{\mathrm{Br}}_{35}.$

• Received 9 August 2000

DOI:https://doi.org/10.1103/PhysRevC.63.054312