Table 3. Proposed Vibrational Assignments of CH₃NO₂ Valence and Rydberg Series Converging to the Ionic Electronic Ground (13a′)⁻¹ and First (12a′)⁻¹ Excited States in the Photon Energy Range 9.0–10.8 (Energies in eV)^a.

energyb	assignment	ΔE (υ3′)	ΔE (υ4′)	ΔE (υ5′)	ΔE (υ8′)	ref (3)
3px/σCN(16a′) ← n̅O/σCN(12a′) + π* (4a″) ← π(2a″)
8.211	000
8.268	801				0.057	8.257
8.313	401		0.102			8.302
8.38(3)(s)	401 + 50/3s(12a′)−1			0.070		8.345
			0.102	0.070	0.057
8.420	3p(13a′)−1					8.437
8.492	501			0.072		8.478
8.565	502			0.073		8.568
8.637	503			0.072		8.687
8.70(4)(s,w)	504			0.067
8.728	502 + 30	0.163				8.732
8.803	503 + 30/3p′(13a′)−1	0.166				8.792
8.869	504 + 30	0.165				8.862
8.930	504 + 30 + 501			0.061
9.043	504 + 30	0.174
9.08(3)(s)	3p(12a′)−1
9.16(7)(s)	501			0.084		9.126
9.23(2)(s,w)	502			0.065
9.32(2)(s,w)	503			0.090
9.379	3d(13a′)−1					9.518
9.450	501/4p′(12a′)−1			0.071
9.530	502			0.080
9.552	4s(13a′)−1					9.541
9.62(6)(s)	501			0.074
9.701	502			0.075
9.77(0)(s)	4p(13a′)−1					9.761
9.85(2)(s,w)	501			0.082
9.91(1)(s)	502/4p′(13a′)−1			0.059		9.806
9.995	503			0.084
10.06(8)(b)	504			0.073
10.445	4p(12a′)−1					10.439
10.629	301/6p′(13a′)−1	0.184				10.628
10.583	6p(13a′)−1/6p′(12a′)−1					10.573
10.656	501			0.073
10.66(5)(s)	6d(13a′)−1
10.763	401		0.098
		0.170	0.098	0.074

^aSee text for details.

^b(s) shoulder structure; (w) weak feature; (b) broad structure (the last decimal of the energy value is given in parentheses for these less-resolved features).