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

TABLE IX.

Convergence of correlation increments for the energy of the 2¹A₁ state, in mh.

Geometry		ΔE(1, 2)	ΔE(3)	ΔE(4)^a	ΔE_Corr^a^,^b	Uncertainty
OM	CAS(2,2)	−663.40	−55.78	−122.76	−841.95	±0.32
	CAS(2,2)*	−437.30	−50.07	−68.15	−555.52	±0.08
	CAS(6,4)*	−324.10	−13.62	−17.66	−355.38	±0.04
	CAS(12,7)*a	−270.89	−7.77	−10.62	−289.28	±0.02
	CAS(12,7)*b	−324.81	−13.29	−17.18	−355.28	±0.17
TS	CAS(2,2)	−707.75	−62.72	−107.60	−878.07	±1.78
	CAS(2,2)*	−488.57	−51.85	−58.30 (−57.78)	−598.72 (−598.20)	±0.11
	CAS(6,4)*	−361.07	−26.71	−26.05	−413.82	±0.15
	CAS(12,7)*a	−295.48	−12.02	−11.69	−319.19	±0.05
	CAS(12,7)*b	−365.01	−26.50	−23.13	−414.64	±0.05
XM	CAS(2,2)	−707.67	−62.61	−104.06	−874.34	±1.12
	CAS(2,2)*	−488.44	−51.69	−57.89	−598.03	±0.18
	CAS(6,4)*	−361.07	−26.70	−25.55	−413.32	±0.04
	CAS(12,7)*a	−295.64	−12.06	−11.69	−319.38	±0.05
	CAS(12,7)*b	−365.01	−25.91	−23.89	−414.81	±0.26
CI	CAS(2,2)	−715.68	−68.07	−112.27	−896.01	±0.35
	CAS(2,2)*	−500.25	−57.72	−65.41 (−64.22)	−623.37 (−622.18)	±0.46
	CAS(6,4)*	−365.55	−26.80	−31.10	−423.44	±0.17
	CAS(12,7)*a	−293.39	−11.71	−12.07	−317.16	±0.02
	CAS(12,7)*b	−369.37	−26.85	−26.32	−422.53	±0.18
RM	CAS(2,2)	−692.63	−80.91	−91.56	−865.11	±0.07
	CAS(2,2)*	−468.81	−68.31	−51.85	−588.97	±0.81
	CAS(6,4)*	−374.37	−35.16	−30.30	−439.83	±0.05
	CAS(12,7)*a	−317.17	−32.77	−24.02	−373.96	±0.24
	CAS(12,7)*b	−367.93	−42.62	−28.34	−438.89	±0.13

^{^a}

The values without parentheses were obtained using the CEEIS extrapolation for the CISDTQ increment ΔE(4). The values in parentheses for the CAS(2,2)* case at the TS and CI geometries were obtained by exact calculation of ΔE(4).

^{^b}

Total correlation energies (up to SDTQ) relative to the respective reference states.