Improved basis selection for the Projected Configuration Interaction method applied to heavy nuclei

TL;DR

This paper enhances the Projected Configuration Interaction method for heavy nuclei by introducing an improved basis selection algorithm, extending the model space to include parity and odd-multipole interactions, and demonstrating accurate results on several isotopes.

Contribution

The paper presents a new algorithm for selecting basis states in the PCI method and extends its applicability to include parity and octupole interactions.

Findings

Good agreement with full CI results for selected nuclei

Enhanced efficiency of the PCI method with the new basis selection

Extended model space to include parity and odd-multipole terms

Abstract

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 for the efficiency of the method, and we propose a newly improved algorithm of selecting the projected basis states. We also extend our method to model spaces that can accomodate both parities, and can include odd-multipole terms in the effective interaction, such as the octupole contributions. %A universal algorithm of the choice of the PCI basis was presented in details. Examples of $^{52}$Fe, $^{56}$Ni, $^{68}$Se, $^{70}$Se and $^{76}$Se are calcualted showing good agreement with the full Configuration Interaction results.