Table 5. Vertical Excitation Energies (Eexc , in eV) of the CT States Obtained with CCSDT and the Relative Error of the Excitation Energies (ΔEexc , in eV) Calculated with Triples Methods as well as Statistics (Mean Error and Standard Deviation (SD)).
| Eexc | ΔEexc |
||||
|---|---|---|---|---|---|
| system | state no. | CCSDT | CCSD(T)(a)* | CC3 | CCSDT-3 |
| ammonia–fluorine | CT1 | 6.64 | –0.01 | –0.12 | –0.03 |
| acetone–fluorine | CT2 | 5.85 | –0.03 | –0.10 | 0.05 |
| pyrazine–fluorine | CT3 | 6.28 | 0.02 | –0.13 | 0.05 |
| CT4 | 6.45 | 0.03 | –0.05 | 0.00 | |
| ammonia–oxygendifluoride | CT5 | 7.04 | –0.01 | –0.21 | 0.05 |
| ammonia–pyrazine | CT7 | 7.49 | 0.24 | –0.03 | 0.04 |
| tetrafluorethylene–ethylene (5 Å) | CT14 | 10.57 | –0.05 | –0.11 | –0.01 |
| mean | 0.03a | –0.11b | 0.02 | ||
| SD | 0.10a | 0.06b | 0.03 | ||
a
If CT7 is not included, the mean error (standard deviation) is −0.01 eV (0.03 eV). See text for explanation.
b
If CT5 is not included, the mean error (standard deviation) is −0.09 eV (0.04 eV). See text for explanation.