. 2016 Mar 10;144(10):104304. doi: 10.1063/1.4942019

TABLE X.

The energy differences {E [CAS(6,4)*] −E [CAS(2,2)*]}and {E [CAS(12,7)*] −E [CAS(2,2)*]}at various excitation levels for the 1¹A₁ state and the 2¹A₁ state.^a

		1¹A₁ energy differences (mh)			2¹A₁ energy differences (mh)
Geometry		CAS(6,4)*	CAS(12,7)*a	CAS(12,7)*b	CAS(6,4)*	CAS(12,7)*a	CAS(12,7)*b
OM	Ref.	−116.77	−120.11	−119.23	−214.94	−214.77	−215.04
	Ref. + SD	−30.29	26.25	−34.62	−101.75	−48.36	−102.54
	Ref. + SDT	−19.00	49.62	−21.87	−65.29	−6.05	−65.76
	Ref. + SDTQ^b	−0.99	75.68	−1.15	−14.80	51.48	−14.79
TS	Ref.	−133.29	−134.52	−133.44	−192.86	−193.42	−193.34
	Ref. + SD	−49.36	12.02	−49.62	−65.36	−0.33	−69.78
	Ref. + SDT	−28.40	41.17	−29.37	−40.21	39.50	−44.43
	Ref. + SDTQ^b	−8.36	73.55	−7.35	−7.96	86.11	−9.26
		(−7.96)^c	(73.94)^c	(−6.96)^c	(−8.48)^c	(85.59)^c	(−9.78)^c
XM	Ref.	−133.56	−134.79	−133.71	−192.63	−193.19	−193.11
	Ref. + SD	−49.44	11.74	−49.69	−65.25	−0.39	−69.68
	Ref. + SDT	−28.33	41.03	−29.88	−40.26	39.25	−43.90
	Ref. + SDTQ^b	−8.39	73.79	−6.64	−7.92	85.45	−9.90
CI	Ref.	−142.49	−143.54	−142.59	−210.72	−211.09	−211.03
	Ref. + SD	−57.85	11.44	−58.12	−76.02	−4.23	−80.15
	Ref. + SDT	−31.91	46.49	−33.46	−45.10	41.78	−49.28
	Ref. + SDTQ^b	−8.59	82.80	−9.74	−10.79	95.12	−10.18
		(−8.18)^c	(84.21)^c	(−9.32)^c	(−11.98)^c	(93.93)^c	(−11.38)^c
RM	Ref.	−56.28	−59.76	−58.69	−164.39	−166.14	−164.81
	Ref. + SD	−21.41	42.80	−22.87	−69.96	−14.50	−71.77
	Ref. + SDT	−18.67	55.93	−20.41	−36.80	21.04	−38.24
	Ref. + SDTQ^b	−7.91	77.75	−7.99	−15.26	51.70	−14.73

^{^a}

The difference between CAS(12,7)*a and CAS(12,7)*b is discussed in Section VI A.

^{^b}

In these rows, all SDTQ energies were obtained by the CEEIS extrapolation.

^{^c}

The energy differences reported in parentheses were obtained using exact CAS(2,2)* energies.