Linear response strength functions with iterative Arnoldi diagonalization

Abstract

We report on an implementation of a new method to calculate random phase approximation (RPA) strength functions with iterative non-Hermitian Arnoldi diagonalization method, which does not explicitly calculate and store the RPA matrix. We discuss the treatment of spurious modes, numerical stability, and how the method scales as the used model space is enlarged. We perform the particle-hole RPA benchmark calculations for double magic nucleus $^{132}\mathrm{Sn}$ and compare the resulting electromagnetic strength functions against those obtained within the standard RPA.