Table 6. The vertical fluorescence energies (ΔE in eV and nm) and oscillator strengths (f in a.u.) for the S₁ state calculated by TD-DFT and CASPT2 at (S₁)_min .

	TD-DFT (in gas)			TD-DFT (in dichloromethane)			CASPT2 (in gas)			Exp.
	ΔE (eV)	ΔE (nm)	f	ΔE (eV)	ΔE (nm)	f	ΔE (eV)	ΔE (nm)	f	ΔE (nm)
1a	4.62	268	0.276	4.33	287	0.446	4.04	307 (326) a	0.382	389
1b	3.46	358	0.137	3.18	390	0.345	2.88	430 (462)	0.092	509
1g	3.48	356	0.164	3.19	389	0.372	2.91	426 (459)	0.101	510
1e	3.14	394	0.072	2.91	425	0.191	2.63	471 (502)	0.078	572
1f	2.82	440	0.046	2.68	463	0.134	2.33	533 (556)	0.060	632

^aThe number in parenthesis is an estimate in dichloromethane.