Answers are grounded in this paper and cite their sources.
A general implementation of the coupled-cluster (CC) single, double, triple, and quadruple excitation (CCSDTQ) method is presented and applied to several molecules, including BH, HF, H2O, and CO with DZP basis sets. Comparisons with full CI show average errors to be 14 μhartree at equilibrium and 26 μhartree at twice Re. CCSDTQ is exact for four electrons and is the first CC method correct through sixth order in perturbation theory.
No takes yet. Share an insight, caveat, or question.
Kucharski et al. (1992) studied this question.
Synapse has enriched 10 related papers. Consider them for comparative context: