Guaranteed convergence for a class of coupled-cluster methods based on Arponen's extended theory

Figures & data

Figure 1. Difference between a canonical and a non-canonical ECC(n)DT computation for the potential curve of HF.

Figure 2. Comparison of CC diagnostics of the C-ECC(1)SD and NC-ECC(1)SD model for the HF potential curve correlated with the multireference character.

Figure 3. Comparison of CC diagnostics of the C-ECC(1)SD and NC-ECC(1)SD model for the H${}_8$ potential curve correlated with the multireference character.

Figure 4. Comparison of CC diagnostics of the C-ECC(2)SD and NC-ECC(2)SD model (lower set of five curves, almost on top of each other) for the N${}_2$ potential curve correlated with the multireference character. The red curve shows diagnostics for NC-ECC(1)SD, indicating the inferiority of this model in the multireference region.