*Article* **Taking the Convergent Close-Coupling Method beyond Helium: The Utility of the Hartree-Fock Theory**

**Igor Bray 1,\*, Xavier Weber 1, Dmitry V. Fursa 1, Alisher S. Kadyrov 1, Barry I. Schneider 2, Sudhakar Pamidighantam 3, Maciej Cytowski 4 and Anatoli S. Kheifets 5**


**Abstract:** The convergen<sup>t</sup> close-coupling (CCC) method was initially developed to describe electron scattering on atomic hydrogen and the hydrogenic ions such as He+. The latter allows implementation of double photoionization (DPI) of the helium atom. For more complex single valence-electron atomic and ionic targets, the direct and exchange interaction with the inner electron core needs to be taken into account. For this purpose, the Hartree-Fock (HF) computer codes developed in the group of Miron Amusia have been adapted. In this brief review article, we demonstrate the utility of the HF technique by examples of electron scattering on Li and the DPI of the H− and Li− ions. We also discuss that modern-day computer infrastructure allows the associated CCC code, and others, to be readily run directly via the Atomic, Molecular and Optical Science Gateway.

**Keywords:** electron–atom scattering; atomic photoionization; many-electron correlation; electronic structure

**PACS:** 32.80.Rm; 32.80.Fb; 42.50.Hz

**arXiv:** 2108.02392
