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Moments of coupled cluster equations

The method of moments of coupled-cluster equations (MMCC) is extended to potential energy surfaces involving multiple bond breaking by developing the quasi-variational (QV) and quadratic (Q) variants of the MMCC theory. The QVMMCC and QMMCC methods are related to the extended CC (ECC) theory, in which products involving cluster operators and their deexcitation counterparts mimic the effects of higher-order clusters. The test calculations for N2 show that the QMMCC and ECC methods can provide spectacular improvements in the description of multiple bond breaking by the standard CC approaches. [Pg.37]

The Method of Moments of Coupled-Cluster Equations An Overview of the Ground-State Formalism... [Pg.42]

Generalization of the method of moments of coupled-cluster equations to excited electronic states Exact formalism... [Pg.49]

NONITERATIVE CORRECTIONS TO COUPLED-CLUSTER AND EQUATION-OF-MOTION COUPLED-CLUSTER ENERGIES DEFINING THE EXACT METHOD OF MOMENTS OF COUPLED-CLUSTER EQUATIONS... [Pg.57]

Kowalski, K. Piecuch, P The method of moments of coupled-cluster equations and the renormalized CCSD[T], CCSD(T), CCSD(TQ), and CCSDT(Q) approaches, ... [Pg.286]

We have overviewed the new approach to the many-electron correlation problem in atoms and molecules, termed the method of moments of coupled-cluster equations (MMCC). The main idea of the MMCC theory is that of the noniterative energy corrections which, when added to the ground- and excited-state energies obtained in approximate CC calculations, recover the exeict energies. We have demonstrated that the MMCC formalism leads to a number of useful approximations, including the renormalized and completely renormalized CCSD(T), CCSD(TQ), and CCSDT(Q) methods for... [Pg.59]

See other pages where Moments of coupled cluster equations is mentioned: [Pg.119]    [Pg.61]    [Pg.31]    [Pg.36]    [Pg.119]    [Pg.61]    [Pg.31]    [Pg.36]    [Pg.366]    [Pg.149]    [Pg.316]    [Pg.12]    [Pg.45]    [Pg.207]    [Pg.338]    [Pg.91]    [Pg.57]    [Pg.376]    [Pg.17]    [Pg.328]    [Pg.73]    [Pg.63]    [Pg.265]    [Pg.474]    [Pg.1174]    [Pg.4]    [Pg.642]    [Pg.644]    [Pg.226]    [Pg.282]    [Pg.137]    [Pg.238]   
See also in sourсe #XX -- [ Pg.126 , Pg.127 ]



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Couple moment)

Coupled equations

Coupled-cluster equations

Coupling equations

Moment equations

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