QCI and related CC approaches: a retrospection

Abstract

The relationship between standard single-reference coupled-cluster (CC) and quadratic configurations interaction (QCI) methods is reviewed from the viewpoint of both past and recent developments in the methodology of post-Hartree–Fock approaches to the many-electron correlation problem, emphasising their advantages and shortcomings on the basis of many-body perturbation theory (MBPT) analysis, the required computational effort, and their practical exploitations.

Keywords:

• quadratic configuration interaction method
• coupled-cluster methods
• many-body perturbation theory

Acknowledgements

Support (J.P.) by the Natural Sciences and Engineering Research Council of Canada is gratefully acknowledged. The author is also indebted to Professors Rodney J. Bartlett, Bogumil Jeziorski, and Piotr Piecuch for helpful advise and stimulating discussions.

Notes

†Also at: Department of Chemistry and (GWC)² – Waterloo Campus, University of Waterloo, Waterloo, Ontario, Canada N2L 3G1.

Additional information

Notes on contributors

Josef Paldus†

†Also at: Department of Chemistry and (GWC)2 – Waterloo Campus, University of Waterloo, Waterloo, Ontario, Canada N2L 3G1.