✦ LIBER ✦

Economical triple excitation equation-of-motion coupled-cluster methods for excitation energies

✍ Scribed by John D. Watts; Rodney J. Bartlett

Publisher: Elsevier Science
Year: 1995
Tongue: English
Weight: 451 KB
Volume: 233
Category: Article
ISSN: 0009-2614
DOI: 10.1016/0009-2614(94)01434-w

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✦ Synopsis

Two triple excitation equation-of-motion coupled-cluster (EOM-CC) methods for excitation energies are derived, implemented, and tested. They are excited state analogues of the CC singles, doubles, and linearized triples (CCSDT-1) iterative method and the CCSD method with a noniterative inclusion of triple excitations (CCSD(T)). EOM-CCSDT-1 and EOM-CCSD(T) results are compared with full configuration interaction, EOM-CCSDT, and experimental data. The new methods describe two-electron transitions significantly better than EOM-CCSD, and are in reasonable agreement with the more complete EOM-CCSDT method.

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