Multireference coupled-cluster Ansatz

Abstract

The origin of the multireference coupled cluster Ansatz for the wave function and the wave operator, discovered in the Quantum Theory Project in 1981, is presented from the historical perspective. Various methods of obtaining the cluster amplitudes – both state-universal and state-selective – are critically reviewed and further prospects of using the multireference coupled cluster Ansatz in electronic structure theory are briefly discussed.

Keywords:

• coupled cluster theory
• multireference cluster Ansatz

Acknowledgements

On this occasion I would like to thank Henk Monkhorst for my five enjoyable visits to QTP and for the pleasure of collaborating with him on several projects throughout the decade of 1980s. I also thank Michael Hanrath, Debashis Mukherjee, Josef Paldus, Piotr Piecuch, and Jiří Pittner for valuable comments on the manuscript.