Table 1. CASSCF(16,16) Results^a with Energy Gaps from the Ground State (G.S.)^b.

state	symmetry	HONO – 1		HONO		LUNO		LUNO + 1		ΔE from G.S. (cm–1)
S0	Ag	S+	1.221	L+	1.043	L–	0.955	S–	0.781	0.00
T0	Bu	S+	1.222	L–	1.000	L+	0.998	S–	0.780	56.76
T1	Bu	L+	1.058	S+	0.997	S–	0.995	L–	0.948	532.93
S1	Ag	C0	1.059	C1	1.011	C′1	0.977	C2	0.951	534.77
T2	Ag	C0	1.043	C1	1.021	C′1	0.975	C2	0.959	549.13
Q0	Ag	C0	1.002	C2	0.999	L–	0.999	S–	0.997	602.74

^aDetailed data for CASSCF are given in Tables S1–S4 in the Supporting Information for CASSCF(4,4), CASSCF(10,10), CASSCF(14,14), and CASSCF(16,16), respectively.

^bUnder columns HONO–LUNO are CASSCF NO identities from Figure 3 and their occupation numbers.