A Computational Perspective on Multichannel Scattering Theory with Applications to Physical and Nuclear Chemistry

In this chapter we discuss a general theoretical framework, based on the generalization of Fano’s approach to discreteecontinuum interaction, able to describe a variety of reso- nant phenomena and decay events, ranging from core-electron spectroscopies to the description of universal properties in ultracold Fermi gases, and from the investigation of b-decay in heavy nuclei to the nucleosynthesis of the elements in stars. This method is capable of analyzing the dynamics of atoms, molecules, and solids under the influ- ence of incident radiation or electronic beams and, simultaneously, to predict quanti- tatively the spectral line shapes correlating their features with the internal dynamic ofC the perturbed system. On the computational side, we demonstrate by using the concept of the multichannel scattering T-matrix that our approach is amenable to effi- cient program implementations for determining numerically continuum wave functions including the main correlation effects. For each application we present a detailed des- cription of the main algorithms and computational procedures used to implement our scattering approach and to limit the computational cost of the calculations.