Table 7. Computed Nature, Excitation Energies (ΔE, in eV), Oscillator Strengths (f), and Electric Dipole Moments (μ, in D) for the Lowest Electronic States in Tryptophan.

State	Nature	ΔECASPT2	f	μ
S0	83.3%...	...	...	6.627
S1	66.8% πr πr*	4.3324	0.0177	6.023
		4.42
S2	58.1%πr πr*	4.77	0.0672	9.684
S3	46.8% nCOπCO*	5.71	0.0358	5.808
S4	69.8% nCOπCO*	5.71	0.002	5.039