**4. Conclusions**

We are grateful for our interactions with Miron Amusia and their group. Here, we have shown how the incorporation of the Self-Consistent Field and Frozen Core Hartree-Fock routines of the group have played a very important role in the development of the CCC

method beyond atomic hydrogen and helium. Not only did this simply broaden the utility of the method but also helped resolve what previously seemed as intractable discrepancies between theory and experiment.

**Author Contributions:** Software, B.I.S., M.C. and S.P.; formal analysis, D.V.F. and A.S.K (Alisher S. Kadyrov); investigation, A.S.K. (Anatoli S. Kheifets); data curation, X.W.; writing—original draft preparation, I.B. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research received no external funding.

**Institutional Review Board Statement:** Not applicable.

**Informed Consent Statement:** Not applicable.

**Data Availability Statement:** The numerical data reported in the present work are available on request from the author.

**Acknowledgments:** The authors gratefully acknowledge the Resources of National Computational Infrastructure facility (NCI Australia), The Pawsey Supercomputer Centre and the Extreme Science and Engineering Discovery Environment (XSEDE), which is supported by National Science Foundation, USA. The Curtin authors are supported by the Australian Research Council.

**Conflicts of Interest:** The authors declare no known conflict of interest.
