Coupled clusters - single and double excitations

Christiansen O, Koch H, J0rgensen P (1996) Perturbative triple excitation corrections to coupled cluster singles and doubles excitation energies. J Chem Phys 105 1451-1459. 

G. E. Scuseria, A. C. Scheiner, T. J. Lee, J. E. Rice, and H. F. Schaefer, J. Chem. Phys., 86, 2881 (1987). The Closed-Shell Coupled-Cluster Single and Double Excitation (CCSD) Model for the Description of Electron Correlation. A Comparison with Configuration Interaction (CISD) Results. 

O. Christiansen, H. Koch, and P. Jorgensen,/. Chem. Phys., 105,1451 (1996). Perturbative Triple Excitation Corrections to Coupled Cluster Singles and Doubles Excitation Energies. 

Christiansen, O., Koch, H., and Jprgensen, P. (19956). The second-order approximate coupled cluster singles and doubles model CC2. Chem. Phys. Lett., 243, 409-418. Christiansen, O., Koch, H., and Jprgensen, P. (1996). Perturbative triple excitation corrections to coupled cluster singles and doubles excitation energies. J. Chem. Phys., 105, 1451-1459. 

CISD... Configuration Interaction. Single and Double Excitation. CCSD... Coupled Cluster. Single and Double Excitation. 

Single-root multi-reference Brillouin-Wigner coupled cluster single- and double-excitations approximation... 

In Section 4.2.3.2, we presented the basic equations of single-root (state-specific) multi-reference Brillouin-Wigner coupled cluster theory. We derived these equations from the single-root (state-specific) multi-reference Brillouin-Wigner perturbation theory presented in Section 4.2.3.1. In this section, we turn our attention to the coupled cluster single- and double-excitations approximation, ccsd. We present... 

Koch H, Jensen HJA, Jorgensen P, Helgaker T (1990) Excitation-energies from the coupled cluster singles and doubles linear response function (CCSDLR) - applications to be, CH+, CO, and H2O. J Chem Phys 93 3345... 

Shiozaki T, Hirao K, Hirata S (2007) Second- and third-order triples and quadruples corrections to coupled-cluster singles and doubles in the ground and excited states. J Chem Phys 126 244106 (11 pages). 

T. D. Crawford, Ph.D. Thesis, University of Georgia, 1996. Many-Body Perturbation Theory and Perturbational Triple Excitation Corrections to the Coupled-Cluster Singles and Doubles Method for High-Spin Open-Shell Systems. 

As has been demonstrated by numerous studies, the accuracy of properties calculated using the GGA DFT methods is, in most cases, comparable to or better than those from ab initio MP2 (Mpller-Plesset second-order perturbation) or CISD (configuration interaction with single and double excitations) methods. In fact, the accuracy of the DFT results in some instances matches those obtained from the much more costly (but, in principle, more exact) CCSD(T) (coupled cluster singles and doubles with a perturbative inclusion of connected triple excitations) method (29) and the ab initio G1 procedure (30). 

CASPT2 complete aetive spaee based second-order perturbation theory CCSD coupled-cluster single and double CCSD(T) CCSD corrected with triple excitations Cl configmation interaction... 

Koch, H., Jensen, H. J. A., Jorgensen, R, Helgaker, T. (1990). Excitation-Enei es from the Coupled Cluster Singles and Doubles Linear Response Function (CCSDLR)—Applications to Be, Ch, Co, and fJ20, /. Chem. Phys., 93, 3345-3350. 

Coupled Cluster Singles and Doubles A non-variational method of solving the Schrddinger equation with the wave function in the form of an exponential operator (with the explicit presence of the single and double excitations, their contribution to be determined in the method) acting on the Hartree-Fock wave function. 

The coupled cluster method is the Cl method based on this wavefunction. One of the noain advantages of this method is to ensure size consistency (see Sect. 3.3) in the selection of electron configurations. In coupled cluster methods, the coupled-cluster singles and doubles (CCSD) method terminates f up to the double excitation... 

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