Table 2.
Couplings between pigments (cm−1) calculated using the PCM-CIS/6-31G method with ɛst = 15 and ɛop = 2.0
| Pigment | PEB50/61C | DBVA | DBVB | PEB82C | PEB158C | PEB50/61D | PEB82D | PEB158D |
|---|---|---|---|---|---|---|---|---|
| PEB50/61C | — | 1 (3) | −37 (−42) | 37 (33) | 23 (29) | 92 (71) | −16 (−15) | 12 (10) |
| DBVA | 1 (3) | — | 4 (−7) | −11 (−17) | 33 (20) | −39 (−44) | −46 (−69) | 3(3) |
| DBVB | −37 (−42) | −4 (−7) | — | 45 (−69) | 3 (4) | 2 (4) | −11 (−17) | 34 (18) |
| PEB82C | 37 (33) | −11 (−17) | −45 (−69) | — | −7 (−7) | −17 (−17) | −3 (−4) | 6 (7) |
| PEB158C | 23 (29) | 33 (20) | 3 (4) | −7 (−7) | — | 18 (16) | 7 (8) | 6 (6) |
| PEB50/61D | 92 (71) | −39 (−44) | 2 (4) | 17 (−17) | 18 (16) | — | 40 (35) | 26 (32) |
| PEB82D | −16 (−15) | −46 (−69) | −11 (−17) | −3 (−4) | 7 (8) | 40 (35) | — | 7 (−7) |
| PEB158D | 12 (10) | 3 (3) | 34 (18) | 6 (7) | 6 (6) | 26 (32) | 7 (−7) | — |
Values predicted by the ideal dipole approximation assuming an effective screening and local field factor s = 0.72 are indicated in parentheses for comparison. The biggest couplings are indicated in bold. The factor s = 9ɛop/(2ɛop+1)2 = 0.72 scaling point dipole couplings is obtained by assuming a Förster screening term (1/ɛop) and Onsager local field factors 3ɛop/(2ɛop+1) for each chromophore (20).