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Unlinked cluster corrections for configuration interaction calculations

✍ Scribed by William L. Luken

Publisher
Elsevier Science
Year
1978
Tongue
English
Weight
322 KB
Volume
58
Category
Article
ISSN
0009-2614

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✦ Synopsis

The four-electron unlinked-cluster contribution to the correlation ener,g of a many-electron atom or molecule is derived for a CI wavefunction composed of a reference determinant and all double excitations from the reference determinant. The resulting formula is valid for small to moderate nambers of electrons, and yields a resuIt of zero for twoand three-electron states For moderate and large numbers of electrons, the formula is very similar to Davidson's

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