Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Cluster expansion methods size-extensive theory

The 1inked-cluster theorem for energy, from the above analysis, is a consequence of the connectivity of T, and the exponential structure for ft. Size-extensivity is thus seen as a consequence of cluster expansion of the wave function. Specfic realizations of the situation are provided by the Bruckner—Goldstone MBPT/25,26/, as indicated by Hubbard/27/, or in the non-perturbative CC theory as indicated by Coester/30,31/, Kummel/317, Cizek/32/, Paldus/33/, Bartlett/21(a)/ and others/30-38/. There are also the earlier approximate many-electron theories like CEPA/47/, Sinanoglu s Many Electron Theory/28/ or the Cl methods with cluster correction /467. [Pg.301]

Cluster expansion representation of a wave-function built from a single determinant reference function [1] has been eminently successful in treating electron correlation effects with high accuracy for closed shell atoms and molecules. The cluster expansion approach provides size-extensive energies and is thus the method of choice for large systems. The two principal modes of cluster expansion developments in Quantum Chemistry have been the use of single reference many-body perturbation theory (SR-MBPT) [2] and the non-perturbative single reference Coupled Cluster (SRCC) theory [3,4]. While the former is computationally economical for the first few orders of the perturbation expansion... [Pg.165]


See other pages where Cluster expansion methods size-extensive theory is mentioned: [Pg.76]    [Pg.178]    [Pg.305]    [Pg.306]    [Pg.3813]    [Pg.34]    [Pg.67]    [Pg.131]    [Pg.168]    [Pg.744]    [Pg.3812]    [Pg.501]    [Pg.347]    [Pg.315]   
See also in sourсe #XX -- [ Pg.301 ]




SEARCH



Cluster expansion methods

Cluster expansion methods size-extensivity

Cluster method

Cluster size

Clusters expansion

Expansion method

Method clustering

Size extensivity

Size methods

Size theory

Theory method

© 2024 chempedia.info