Improved basis selection for the projected configuration interaction method applied to medium-heavy nuclei

In a previous paper, we proposed a projected configuration interaction method that uses sets of axially deformed single-particle states to build up the many-body basis. We show that the choice of the basis set is essential to the efficiency of the method, and we propose a newly improved algorithm for selecting the projected basis states. We also extend our method to model spaces that can accommodate both parities and can include odd-multipole terms in the effective interaction, such as the octupole contributions. Examples of ⁵⁶Ni, ⁶⁸Se, ⁷⁰Se, and ⁷⁶Se are calculated showing good agreement with the full configuration interaction results.