Table 2. VEEs (E, in eV) of Gas-Phase Optimized Chl a Using DLPNO–STEOM-CCSDa.
| excited state | E (eV) | frontier molecular orbitals | % contribution | |μ| (Debye) |
|---|---|---|---|---|
| S1 (Qy) | 1.746 (0.219) | HOMO → LUMO, HOMO – 1 → LUMO + 1 | 0.69, 0.16 | 5.76 |
| S2 (Qx) | 2.240 (0.040) | HOMO – 1 → LUMO, HOMO → LUMO + 1 | 0.59, 0.28 | 2.15 |
| S3 (Bx) | 3.172 (1.304) | HOMO → LUMO + 1, HOMO – 1 → LUMO | 0.49, 0.22 | 10.34 |
| S4 (By) | 3.397 (1.231) | HOMO – 1 → LUMO + 1, HOMO → LUMO | 0.61, 0.15 | 9.79 |
a
Oscillator strengths are shown in parenthesis. The major contributions in the canonical basis associated with the first four electronic states are described. The magnitude of the TDM (μ, in Debye) associated with the excited state is also provided.