Back Metoda vázaných klastrů Czech Coupled Cluster German Méthode du cluster couplé French Metodo Coupled Cluster Italian 結合クラスター法 Japanese Çiftlenmiş küme Turkish Зв'язані кластери Ukrainian 耦合簇方法 Chinese
Coupled cluster (CC) is a numerical technique used for describing many-body systems. Its most common use is as one of several post-Hartree–Fock ab initio quantum chemistry methods in the field of computational chemistry, but it is also used in nuclear physics. Coupled cluster essentially takes the basic Hartree–Fock molecular orbital method and constructs multi-electron wavefunctions using the exponential cluster operator to account for electron correlation. Some of the most accurate calculations for small to medium-sized molecules use this method.[1][2][3]
The method was initially developed by Fritz Coester and Hermann Kümmel in the 1950s for studying nuclear-physics phenomena, but became more frequently used when in 1966 Jiří Čížek (and later together with Josef Paldus) reformulated the method for electron correlation in atoms and molecules. It is now one of the most prevalent methods in quantum chemistry that includes electronic correlation.
CC theory is simply the perturbative variant of the many-electron theory (MET) of Oktay Sinanoğlu, which is the exact (and variational) solution of the many-electron problem, so it was also called "coupled-pair MET (CPMET)". J. Čížek used the correlation function of MET and used Goldstone-type perturbation theory to get the energy expression, while original MET was completely variational. Čížek first developed the linear CPMET and then generalized it to full CPMET in the same work in 1966. He then also performed an application of it on the benzene molecule with Sinanoğlu in the same year. Because MET is somewhat difficult to perform computationally, CC is simpler and thus, in today's computational chemistry, CC is the best variant of MET and gives highly accurate results in comparison to experiments.[4][5][6]
- ^ Kümmel, H. G. (2002). "A biography of the coupled cluster method". In Bishop, R. F.; Brandes, T.; Gernoth, K. A.; Walet, N. R.; Xian, Y. (eds.). Recent progress in many-body theories Proceedings of the 11th international conference. Singapore: World Scientific Publishing. pp. 334–348. ISBN 978-981-02-4888-8.
- ^ Cramer, Christopher J. (2002). Essentials of Computational Chemistry. Chichester: John Wiley & Sons, Ltd. pp. 191–232. ISBN 0-471-48552-7.
- ^ Shavitt, Isaiah; Bartlett, Rodney J. (2009). Many-Body Methods in Chemistry and Physics: MBPT and Coupled-Cluster Theory. Cambridge University Press. ISBN 978-0-521-81832-2.
- ^ Čížek, Jiří (1966). "On the Correlation Problem in Atomic and Molecular Systems. Calculation of Wavefunction Components in Ursell-Type Expansion Using Quantum-Field Theoretical Methods". The Journal of Chemical Physics. 45 (11): 4256–4266. Bibcode:1966JChPh..45.4256C. doi:10.1063/1.1727484.
- ^ Sinanoğlu, O.; Brueckner, K. (1971). Three approaches to electron correlation in atoms. Yale Univ. Press. ISBN 0-300-01147-4. See also references therein.
- ^ Si̇nanoğlu, Oktay (1962). "Many-Electron Theory of Atoms and Molecules. I. Shells, Electron Pairs vs Many-Electron Correlations". The Journal of Chemical Physics. 36 (3): 706–717. Bibcode:1962JChPh..36..706S. doi:10.1063/1.1732596.