Experimental interest in nuclei far from stability, especially due to proposed advancements in rare isotope facilities, has stimulated improvements in theoretical predictions for exotic isotopes. However, standard techniques developed for nuclear structure calculations, configuration interaction theory and energy density functional methods lack either the generality or the accuracy necessary for reliable calculations away from stability. Hybrid methods, which combine configuration interaction theory and energy density functional methods in order to exploit their beneficial properties, are currently under investigation for improved theoretical capabilities. An improved technique to produce nuclear Hamiltonians has been developed, implementing renormalization group methods, many-body perturbative techniques and energy density functional methods. Connection to the underlying physics is a primary focus, limiting the number of free parameters necessary in the procedure. The main benefit of this approach is the improvement in the quality of effective interactions outside of standard model spaces. Applications to the island of inversion region and for 42Si display the viability of the method and motivate possibilities for future research.
