Table 4. Computed Nature, Excitation Energies (ΔE, in eV), Oscillator Strengths (f), and Electric Dipole Moments (μ, in D) for the Lowest Electronic States in Tyrosine.

state	nature	ΔECASPT2	f	μ
S0	85.6%...	...	...	3.28
S1	75.4% πr πr*	4.49(4.40)27	0.0056	3.27
S2	81.0% nCO πCO*	5.54	0.0019	2.18
S3	65.5% πr πr*	5.67	0.006	4.01
S4	79.1% πr πr*	5.98	0.759	3.36