Coupled-cluster theory and the method of moments

Research output: Article

4 Citations (Scopus)

Abstract

Following an idea by Jankowski et al. (Theor. Chim. Acta 80, (1991), 223), we investigate the effect of minimizing the sum of squared moments of the Hamiltonian with respect to the coupled-cluster singles and doubles (CCSD) amplitudes. If considering moments built with just singly and doubly excited functions, the ordinary CCSD amplitudes are recovered. When including higher excitations, the resulting energies are usually worse than those obtained from standard CCSD theory, but moment-optimized CCSD wave functions are slightly more accurate than standard ones. Examples where moment-minimized CCSD energies are more realistic are represented by the dissociation profile of the N2 molecule described by single reference CCSD, or the potential curve of the water molecule for symmetric dissociation.

Original languageEnglish
Pages (from-to)17-23
Number of pages7
JournalJournal of Molecular Structure: THEOCHEM
Volume768
Issue number1-3
DOIs
Publication statusPublished - jún. 4 2006

Fingerprint

method of moments
Method of moments
Hamiltonians
Molecules
Wave functions
moments
Water
dissociation
molecules
wave functions
energy
curves
profiles
water
excitation

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry
  • Computational Theory and Mathematics
  • Atomic and Molecular Physics, and Optics

Cite this

Coupled-cluster theory and the method of moments. / Rolik, Z.; Szabados, A.; Kohalmi, D.; Surján, P.

In: Journal of Molecular Structure: THEOCHEM, Vol. 768, No. 1-3, 04.06.2006, p. 17-23.

Research output: Article

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