ISSN:
1432-2234
Keywords:
Coupled cluster method
;
Valence bond (VB) wave functions
;
VB corrected CCSD method
;
Cluster analysis
;
Correlation effects
;
PPP Hamiltonian
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Summary The recently proposed valence bond (VB) corrected single reference (SR) coupled cluster method with singly and doubly excited cluster components (CCSD) [Paldus and Planelles, Theor Chim Acta 89, 13–31 (1994)] is tested using a number of simple yet typical Pariser-Parr-Pople (PPP) π-electron model systems, including both cyclic and linear polyenes. The cluster analysis of various approximate VB wave functions, obtained with the PPP-VB approach [Li and Paldus, J Mol Struct (Theochem) 229, 249 (1991)], is carried out and the resulting three- and four-body connected cluster components are employed in the VB corrected CCSD method. The cluster structure and the correlation energies obtained are compared to full configuration interaction (FCI) or full VB (FVB) results, representing the exact solutions for these models, and the performance and potential of the CCSD-VB approach are discussed.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01167280
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