ISSN:
0040-5744
Keywords:
Key words: Intermediate Hamiltonians
;
Total dressing
;
Size-consistent configuration interactions
;
Linked and unlinked diagrams
;
Spectroscopic constants
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Summary. A previously proposed procedure including the linked and unlinked contributions due to Triple and Quadruple excitations into a size-consistent SDCI-like model has been applied to HF and F2 single-bond systems. The procedure is a non-iterative approximation to the more general total dressing model, which is based on the intermediate Hamiltonians theory. Three basis sets have been employed: the correlation consistent cc-pVTZ basis, a similar one including 3d1f polarization functions, and another including one set of g polarization functions. Excellent agreement with experiment and high-quality calculations is obtained for both equilibrium distances and spectroscopic constants. The possibilities of the method in treating single-bond breaking are also demonstrated. Finally, the Linked and Non-Linked contributions from Triple and Quadruple excitations are analysed separately and it is suggested that the addition of the linked triples to the size-consistent SDCI is sufficient to have quantitatively correct spectroscopic properties in going from the size-consistent SDCI to nearly experimental values.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01125949
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