Table 6. Relative Error of the Calculated Excitation Energies (ΔEexc , in eV) with Respect to CCSDT-3 Results for CT States.
| ΔEexc |
||||||||
|---|---|---|---|---|---|---|---|---|
| system | state no. | ADC(2) | CC2 | CCSD(2) | CCSD | STEOM | CCSD(T)(a)* | CC3 |
| ammonia–fluorine | CT1 | –0.63 | –0.65 | 0.11 | 0.28 | –0.19 | 0.01 | –0.09 |
| acetone–fluorine | CT2 | –0.77 | –0.72 | 0.20 | 0.38 | –0.05 | –0.07 | –0.15 |
| pyrazine–fluorine | CT3 | –0.58 | –0.70 | 0.49 | 0.44 | 0.01 | –0.03 | –0.18 |
| CT4 | –0.09 | –0.18 | 0.30 | 0.27 | 0.10 | 0.03 | –0.06 | |
| ammonia–oxygendifluoride | CT5 | –0.80 | –0.76 | 0.03 | 0.24 | –0.03 | –0.06 | –0.27 |
| acetone–nitromethane | CT6 | –0.67 | –0.36 | 0.36 | 0.33 | –0.08 | 0.00 | –0.14 |
| ammonia–pyrazine | CT7 | –0.25 | –0.22 | 0.37 | 0.40 | –0.15 | 0.20 | –0.06 |
| pyrazine–pyrrole (H-bonded) | CT8 | –0.15 | –0.21 | 0.53 | 0.32 | 0.03 | –0.02 | –0.12 |
| CT9 | –0.24 | –0.25 | 0.52 | 0.33 | 0.00 | –0.01 | –0.14 | |
| CT10 | –0.22 | –0.24 | 0.38 | 0.30 | 0.02 | –0.03 | –0.12 | |
| pyrazine–pyrrole (stacked) | CT11 | –0.15 | –0.15 | 0.37 | 0.20 | –0.08 | –0.01 | –0.08 |
| CT12 | –0.15 | –0.14 | 0.24 | 0.16 | –0.11 | –0.02 | –0.07 | |
| CT13 | –0.12 | –0.10 | 0.32 | 0.18 | –0.16 | –0.01 | –0.08 | |
| ethylene-tetrafluoroethylene | CT14 | –0.28 | –0.40 | 0.18 | 0.31 | 0.05 | –0.04 | –0.10 |
| mean | –0.36 | –0.36 | 0.31 | 0.30 | –0.05 | 0.00a | –0.12b | |
| SD | 0.26 | 0.24 | 0.15 | 0.08 | 0.09 | 0.06a | 0.05b | |
a
If CT7 is not included, the mean error (standard deviation) is −0.02 eV (0.03 eV). See text for explanation.
b
If CT5 is not included, the mean error (standard deviation) is −0.11 eV (0.04 eV). See text for explanation.