Basis Set Effects in the Description of the Cl-O Bond in ClO and XClO/ClOX Isomers (X = H, O, and Cl) Using DFT and CCSD(T) Methods

Table 5

Enthalpies of reaction and derived standard enthalpies of formation (in kcal/mol) for water and hypochlorous acid using different models.

Basis set	H2O				HOCl
	HOH ⟶ 2H + O		HOH ⟶ H2 + 1/2O2		HOCl ⟶ H + Cl + O		2HOCl ⟶ H2 + Cl2 + O2
	cc-pVDZ	197.41	6.05	47.85	−8.15	132.90	7.75	23.09	−11.55
aug-cc-pVDZ	208.10	−4.64	56.56	−16.86	142.63	−1.98	36.66	−18.33
cc-pVTZ	213.61	−10.15	54.52	−14.82	150.00	−9.35	32.72	−16.36
aug-cc-pVTZ	216.91	−13.45	57.01	−17.31	153.20	−12.55	36.20	−18.10
cc-pVQZ	218.44	−14.98	56.84	−17.14	155.41	−14.76	35.46	−17.73
aug-cc-pVQZ	219.79	−16.33	57.71	−18.01	156.93	−16.28	36.83	−18.41
cc-pV5Z	220.09	−16.63	57.65	−17.95	157.81	−17.16	36.59	−18.30
aug-cc-PV5Z	220.49	−17.03	57.80	−18.11	158.43	−17.78	36.94	−18.47
cc-pV6Z	220.62	−17.16	57.78	−18.09	158.66	−18.01	36.81	−18.40
aug-cc-PV6Z	220.77	−17.31	57.81	−18.11		−18.15		−18.45