Scattering of weakly interacting massive particles fromGe73

We use a ‘‘hybrid’’ method, mixing variationally determined triaxial nuclear Slater determinants, to calculate the response of ${}_{}{}^{73}{}_{}{}^{}\mathrm{Ge}$ to hypothetical dark-matter particles such as neutralinos. The method is a hybrid in that rotational invariance is approximately restored prior to variation and then fully restored before the mixing of intrinsic states. We discuss such features of ${}_{}{}^{73}{}_{}{}^{}\mathrm{Ge}$ as shape coexistence and triaxiality, and their effects on spin-dependent neutralino cross sections. Our calculations yield a satisfactory quadrupole moment and an accurate magnetic moment in this very complicated nucleus, suggesting that the spin structure and thus the axial-vector response to dark-matter particles is modeled well.