III.G.1.a.

Comparison of levels of theory for O-O

Click on an entry for a histogram of the values.
The subscript refers to how many bonds of that type have been calculated.

average calculated bond lengths (Å)

Methods with predefined basis sets
semi-empirical	AM1	1.1752 11
	PM3	1.3090 20
	PM6	1.3077 32
composite	G2	1.3568 28
	G3	1.3514 29
	G3B3	1.3861 27
	CBS-Q	1.3440 27

average calculated bond lengths (Å)

Methods with standard basis sets
		STO-3G	3-21G	3-21G*	6-31G	6-31G*	6-31G**	6-31+G**	6-311G*	6-311G**	6-31G(2df,p)	6-311+G(3df,2p)	TZVP	cc-pVDZ	cc-pVTZ	cc-pVQZ	aug-cc-pVDZ	aug-cc-pVTZ	aug-cc-pVQZ	cc-pV(T+d)Z	cc-pCVDZ	cc-pCVTZ	Sadlej_pVTZ
hartree fock	HF	1.4002 28	1.4467 28	1.4470 27	1.4155 27	1.3412 31	1.3577 28	1.3504 30	1.3368 29	1.3434 28	1.3481 28	1.2840 11	1.3354 35	1.3412 29	1.3484 29	1.2661 19	1.2870 25	1.2817 28	1.2373 12	1.2737 1			1.1640 1
hartree fock	ROHF	1.3049 9	1.4625 16	1.4604 16	1.4179 16	1.3504 18	1.3712 16	1.3700 16	1.3610 16	1.3887 13	1.2306 9	1.1508 1		1.3648 16	1.3619 16	1.2223 9	1.2468 11	1.2441 11	1.2309 8
density functional	LSDA	1.4444 27	1.4860 28	1.4867 28	1.4786 26	1.4149 27	1.4171 27	1.4253 27	1.4099 27	1.4105 27	1.3420 25			1.4083 27	1.4081 27	1.2674 8	1.3478 25	1.3764 12	1.2730 7
	SVWN		1.4121 22			1.3358 20		1.3270 22
	BLYP	1.4953 29	1.5340 29	1.5355 30	1.5164 29	1.4578 28	1.4603 29	1.4671 28	1.4876 28	1.4496 28	1.4545 28			1.4567 30	1.4518 29		1.3443 9
	B1B95	1.4488 27	1.5029 28	1.5043 28	1.4769 27	1.4013 26	1.3947 27	1.3907 28	1.3876 27	1.3879 27	1.3890 24			1.3899 27	1.3862 27	1.2614 8	1.3099 23	1.3083 12	1.2591 8
	B3LYP	1.4788 29	1.5009 31	1.5052 30	1.4804 29	1.3955 30	1.3977 29	1.4207 30	1.3909 29	1.4277 20	1.3867 28	1.2878 8	1.3789 35	1.4017 29	1.3962 29	1.2906 12	1.3424 25	1.3567 26	1.2887 12	1.1950 1			1.2123 1
	B3LYPultrafine					1.3903 26		1.2923 7
	B3PW91	1.4749 20	1.4969 30	1.4986 30	1.4714 29	1.3847 28	1.3869 29	1.3861 29	1.3796 29	1.4162 20	1.3767 28			1.3842 30	1.3864 28		1.3007 9
	mPW1PW91	1.4794 19	1.4659 29	1.4993 21	1.4637 29	1.3784 28	1.3868 28	1.3794 29	1.3728 29	1.3731 29	1.3703 28			1.3822 28	1.3709 28		1.3063 11	1.3839 3
	M06-2X	1.9774 3	1.9910 3	1.9910 3	1.9822 3	1.3954 24	1.9398 3	1.9406 3	1.9376 3	1.9377 3	1.9342 3			1.9391 3	1.9345 3		1.4242 1	1.4239 1
	PBEPBE	1.4901 21	1.5207 29	1.5630 21	1.5455 20	1.4387 27	1.4317 28	1.4638 27	1.4466 28	1.4413 29	1.4346 28	1.3219 9		1.4505 28	1.4360 28	1.2910 8	1.7167 3	1.4548 12	1.2979 7				1.2110 1
	PBEPBEultrafine					1.3490 10		1.2819 2
	HSEh1PBE	1.9889 3	1.9955 3	1.9955 3	1.9908 3	1.3973 25	1.9436 3	1.9446 3	1.9413 3	1.9417 3	1.9386 3			1.9440 3	1.9386 3		1.4318 1	1.4310 1
Moller Plesset perturbation	MP2FC	1.5060 17	1.5139 29	1.5161 28	1.5010 27	1.4179 30	1.4178 29	1.4212 31	1.3993 30	1.3998 30	1.4112 27		1.3875 36	1.4083 30	1.3977 29	1.2520 5	1.3475 24	1.3709 16	1.2503 5	1.2664 1	1.3168 4	1.3100 4	1.2388 1
	MP2FU	1.5059 17	1.5171 25	1.5502 20	1.5377 20	1.4164 30	1.4170 29	1.4204 31	1.3980 30	1.4304 21	1.4300 21			1.4121 28	1.4181 23	1.2844 6	1.3186 12	1.3434 12	1.2636 2	1.2613 1	1.3159 4	1.3079 4
	ROMP2	1.7219 9	1.7696 9	1.8224 8	1.6846 11	1.6162 11	1.6153 11	1.6155 11	1.5943 11	1.5950 11	1.5950 11			1.6026 11	1.5963 11	1.3170 6	1.3265 8	1.2990 8	1.3169 3
	MP3					1.3926 27
	MP4		1.5850 17	1.4887 2	1.4909 2	1.4434 24	1.3406 1	1.3437 1	1.3168 5	1.4517 17				1.3310 1	1.3458 16
	B2PLYP	1.9953 3	2.0095 3	2.0095 3	2.0126 3	1.4268 25	1.9586 3	1.4278 25	1.9542 3	1.9548 3	1.9235 3			1.9594 3	1.9607 3		1.4606 1	1.4045 1
Configuration interaction	CID		1.5115 20	1.5123 20	1.4709 21	1.3823 29	1.3238 1	1.3244 1	1.3704 26					1.3131 1	1.3069 1
Configuration interaction	CISD		1.5027 23	1.5031 23	1.4837 22	1.3863 29	1.3293 1	1.3300 1	1.3943 22					1.3188 1	1.3106 1
Quadratic configuration interaction	QCISD	1.4838 2	1.5514 25	1.5812 19	1.5528 19	1.4144 27	1.4449 22	1.4138 27	1.4010 27	1.4089 22	1.4211 19	1.2480 2		1.4146 27	1.3665 22		1.3534 5	1.3966 3
	QCISD(T)		1.4760 1	1.4760 1		1.4375 26	1.3535 1	1.3757 4	1.3114 5	1.5250 1		1.2707 2		1.4388 18	1.4304 18		1.3026 10	1.3746 2
	QCISD(TQ)					1.2733 3												1.2138 1
Coupled Cluster	CCD	1.4804 2	1.5314 20	1.5328 20	1.4972 22	1.3977 29	1.4285 21	1.4136 23	1.3867 27	1.4070 19	1.4071 19	1.2347 2		1.3946 28	1.4048 17		1.3080 14	1.3662 5
	CCSD		1.4580 1	1.4580 1	1.4392 1	1.3994 26	1.3442 1	1.3525 4	1.2930 5	1.4700 2		1.2440 2		1.5607 8	1.5489 8		1.2592 2
	CCSD(T)		1.2943 2			1.4233 26	1.3302 5	1.3210 6	1.3097 5	1.2848 3	1.2116 1	1.2482 3		1.4344 20	1.3782 24	1.3129 1	1.3372 16	1.3501 6			1.2614 3	1.2539 3
	CCSD(T)=FULL					1.5045 13								1.5595 8	1.1584 8		1.3760 5	1.2830 4			1.2605 3	1.2520 3

average calculated bond lengths (Å)

Methods with effective core potentials (select basis sets)
		CEP-31G	CEP-31G*	CEP-121G	CEP-121G*	LANL2DZ	SDD
hartree fock	HF	1.4170 27	1.3684 28	1.4152 27	1.3653 28	1.4130 27	1.4129 27
density functional	B1B95	1.3828 11	1.3310 11
density functional	B3LYP	1.4923 28	1.4199 28	1.5047 28	1.4162 28	1.4971 27	1.4902 28
Moller Plesset perturbation	MP2FC	1.5106 27	1.4375 28	1.5211 24	1.4340 28	1.5086 27	1.5214 25

For descriptions of the methods (AM1, HF, MP2, ...) and basis sets (3-21G, 3-21G*, 6-31G, ...) see the glossary in section I.C. Predefined means the basis set used is determined by the method.