A fifth-order perturbation comparison of electron correlation theories
Abstract
Electron correlation theories such as configuration interaction (CI), coupled-cluster theory (CC), and quadratic configuration interaction (QCI) are assessed by means of a Møller-Plesset perturbation expansion of the correlation energy up to fifth order. The computational efficiencies and relative merits of the different techniques are outlined. A new augmented version of coupled-cluster theory, denoted as CCSD(T), is proposed to remedy some of the deficiencies of previous augmented coupled-cluster models.
- Publication:
-
Chemical Physics Letters
- Pub Date:
- May 1989
- DOI:
- 10.1016/S0009-2614(89)87395-6
- Bibcode:
- 1989CPL...157..479R