Table 2. Calculated Electronic Parameters of the Model Compound: Transition Wavelengths, λ, Oscillator Strengths, f, Transition Dipoles, μ, Transition Types, and Orbital Configurations of F_M In Vacuo for the Main Transitions (HOMOs and LUMOs Represent the Highest Occupied and the Lowest Unoccupied Molecular Orbitals, Respectively).

tautomer form	transition	λ, nm	f	|μ|, D	transition type	main configuration
N	S0 → S1absorption	381	0.5137	6.4472	π → π*	0.98 |HOMO → LUMO>
	S0 → S2	310	0.0594	0.6056	π → π*	0.93 |HOMO-1 → LUMO
	S0 → S3	305	0.0000	0.0001	n → π*	0.98 |HOMO-4 → LUMO>
	S1 → S0fluorescence	430	0.4432	6.2735	π → π*	0.99 |HOMO → LUMO>
T	S0 → S1	499	0.5002	8.2124	π → π*	0.99 |HOMO → LUMO>
	S0 → S2	369	0.0000	0.0004	n → π*	0.97 |HOMO-2 → LUMO>
	S0 → S3	356	0.1361	1.5968	π → π*	0.94 |HOMO-1 → LUMO>
	S1 → S0fluorescence	548	0.4123	7.4321	π → π*	0.99 |HOMO → LUMO>