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 4

Optimum ClO bond length (in A) calculated at different theoretical levels for the three species HClO, ClO, and HOCl.

Species	Method	6-31G(d)	6–311++G(2df.2pd)	aug-cc-pV6Z
HClO	MP2	1.5961	1.5492
	CCSD(T)	1.6493	1.5806	1.5568
	PW91PW91	1.6095	1.5720	1.5566
	TPSSTPSS	1.6200	1.5785	1.5626
	B3LYP	1.6262	1.5775	1.5594
	PBE0	1.5955	1.5539	1.5381
	M06	1.5944	1.5496	1.5310
	M06-2X	1.6117	1.5643	1.5501
	BMK	1.6350	1.5869	1.5646
	B2PLYP	1.6216	1.5715	1.5540
ClO	MP2	1.6088	1.5614
	CCSD(T)	1.6287	1.5885	1.5694
	PW91PW91			1.5778
	TPSSTPSS			1.5848
	B3LYP	1.6195	1.5844	1.5736
	PBE0	1.5999	1.5665	1.5563
	M06	1.5970	1.5661	1.5563
	M06-2X	1.5967	1.5633	1.5545
	BMK	1.6199	1.5842	1.5693
	B2PLYP	1.6093	1.5758	1.5631
HOCl	MP2	1.7183	1.6946
	CCSD(T)	1.7355	1.7072	1.6899
	PW91PW91	1.7384	1.7158	1.7088
	TPSSTPSS	1.7419	1.7197	1.7128
	B3LYP	1.7272	1.7053	1.6980
	PBE0	1.7010	1.6807	1.6739
	M06	1.6987	1.6785	1.6717
	M06-2X	1.6940	1.6765	1.6706
	BMK	1.7125	1.6917	1.6830
	B2PLYP	1.7235	1.7017	1.6924