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A test of the approximate coupled cluster doubles approximation

✍ Scribed by Svein Sæbø; Péter Pulay

Publisher
Elsevier Science
Year
1986
Tongue
English
Weight
463 KB
Volume
131
Category
Article
ISSN
0009-2614

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✦ Synopsis

The approximate coupled cluster doubles (ACCD) approximation is tested, both at the infinite-order level and at fourth order of many-body perturbation theory. It is found that in the presence of strong pair coupling, i.e. for most molecules, there is a substantial deviation between the ACCD and the full representation of unlinked clusters of double substitutions at the additive fourthorder level.

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